Witkowski Mark R

SEC source: 0001856525-26-000023 · wk-form4_1773444243.xml · derivative · entry 3

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 131,382

Underlying: Class A Common Stock · 131,382 shares

Expires 2036-03-12

F3 · derivative.exercise_date: The options vest in three equal installments on March 11, 2027, March 11, 2028 and March 11, 2029, subject to the terms of the associated Participant Stock Option Agreement.

SEC source: 0001856525-26-000023 · wk-form4_1773444243.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 51,119

F2 · shares: Represents RSUs granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock of the Issuer. The RSUs vest in three equal annual installments on March 11, 2027, March 11, 2028 and March 11, 2029, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-26-000023 · wk-form4_1773444243.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,747

F1 · shares: Represents shares withheld by the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units ("RSUs") granted to the reporting person.

SEC source: 0001856525-26-000005 · wk-form4_1773263439.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 34,432

F1 · shares: Represents shares withheld by the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units granted to the reporting person.

SEC source: 0001856525-26-000005 · wk-form4_1773263439.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,369

F1 · shares: Represents shares withheld by the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units granted to the reporting person.

SEC source: 0001856525-25-000162 · wk-form4_1755723230.xml · derivative · entry 5

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 100,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F5 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F1 · kind: On August 18, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 100,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F1 · shares: On August 18, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 100,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F5 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F5 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-25-000162 · wk-form4_1755723230.xml · derivative · entry 4

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Class A Common Stock · 100,000 shares

Expires not disclosed

F5 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F5 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On August 18, 2025, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of February 13, 2024 (as amended, the "LLC Agreement"), 100,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 100,000 Paired Interests.

F5 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F5 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-25-000162 · wk-form4_1755723230.xml · derivative · entry 3

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 616,250

Underlying: Class A Common Stock · 100,000 shares

Expires not disclosed

F5 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F5 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F2 · shares: On August 18, 2025, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of February 13, 2024 (as amended, the "LLC Agreement"), 100,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 100,000 Paired Interests.

F5 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F5 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F6 · ownership.direct: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-25-000162 · wk-form4_1755723230.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 35,847

F3 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on April 17, 2025.

F4 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $63.8250 to $64.7650 per share. The reporting person will provide to the Issuer, or the Securities and Exchange Commission staff, upon request, information regarding the number of shares sold at each price within the range.

SEC source: 0001856525-25-000162 · wk-form4_1755723230.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 135,847

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: On August 18, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 100,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F2 · shares: On August 18, 2025, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of February 13, 2024 (as amended, the "LLC Agreement"), 100,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 100,000 Paired Interests.

SEC source: 0001856525-25-000151 · wk-form4_1753133828.xml · derivative · entry 6

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 100,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F6 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F1 · kind: On July 17, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 100,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F1 · shares: On July 17, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 100,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F6 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-25-000151 · wk-form4_1753133828.xml · derivative · entry 5

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Class A Common Stock · 100,000 shares

Expires not disclosed

F6 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On July 17, 2025, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of February 13, 2024 (as amended, the "LLC Agreement"), 100,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 100,000 Paired Interests.

F6 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-25-000151 · wk-form4_1753133828.xml · derivative · entry 4

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 716,250

Underlying: Class A Common Stock · 100,000 shares

Expires not disclosed

F6 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F6 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F2 · shares: On July 17, 2025, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of February 13, 2024 (as amended, the "LLC Agreement"), 100,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 100,000 Paired Interests.

F6 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F6 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · ownership.direct: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-25-000151 · wk-form4_1753133828.xml · nonDerivative · entry 3

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 35,847

F3 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on April 17, 2025.

F5 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $61.4550 to $61.8200 per share. The reporting person will provide to the Issuer, or the Securities and Exchange Commission staff, upon request, information regarding the number of shares sold at each price within the range.

SEC source: 0001856525-25-000151 · wk-form4_1753133828.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 63,516

F3 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on April 17, 2025.

F4 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $60.4500 to $61.4500 per share. The reporting person will provide to the Issuer, or the Securities and Exchange Commission staff, upon request, information regarding the number of shares sold at each price within the range.

SEC source: 0001856525-25-000151 · wk-form4_1753133828.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 135,847

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: On July 17, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 100,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F2 · shares: On July 17, 2025, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of February 13, 2024 (as amended, the "LLC Agreement"), 100,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 100,000 Paired Interests.

SEC source: 0001856525-25-000087 · wk-form4_1743633062.xml · derivative · entry 2

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 73,458

Underlying: Class A Common Stock · 73,458 shares

Expires 2035-03-31

F2 · derivative.exercise_date: The options vest in three equal installments on March 11, 2026, March 11, 2027 and March 11, 2028, subject to the terms of the associated Participant Stock Option Agreement.

SEC source: 0001856525-25-000087 · wk-form4_1743633062.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,847

F1 · shares: Represents restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock of the Issuer. The RSUs vest in three equal annual installments on March 11, 2026, March 11, 2027 and March 11, 2028, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-25-000071 · wk-form4_1742258981.xml · derivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 53,094

Underlying: Class A Common Stock · 53,094 shares

Expires 2035-03-13

F2 · derivative.exercise_date: The options vest in three equal installments on March 11, 2026, March 11, 2027 and March 11, 2028, subject to the terms of the associated Participant Stock Option Agreement.

SEC source: 0001856525-25-000071 · wk-form4_1742258981.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,755

F1 · shares: Represents restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock of the Issuer. The RSUs vest in three equal annual installments on March 11, 2026, March 11, 2027 and March 11, 2028, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-25-000053 · wk-form4_1741900306.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,459

F1 · shares: Represents shares withheld by the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units ("RSUs") granted to the reporting person.

SEC source: 0001856525-25-000039 · wk-form4_1741733583.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,384

F1 · shares: Represents shares withheld by the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units ("RSUs") granted to the reporting person.

SEC source: 0001856525-25-000039 · wk-form4_1741733583.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,380

F1 · shares: Represents shares withheld by the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units ("RSUs") granted to the reporting person.

SEC source: 0001856525-24-000057 · wk-form4_1715380692.xml · derivative · entry 5

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 50,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F1 · kind: On May 8, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 50,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F1 · shares: On May 8, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 50,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-24-000057 · wk-form4_1715380692.xml · derivative · entry 4

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 50,000

Underlying: Class A Common Stock · 50,000 shares

Expires not disclosed

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On May 8, 2024, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 50,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 50,000 Paired Interests.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-24-000057 · wk-form4_1715380692.xml · derivative · entry 3

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 816,250

Underlying: Class A Common Stock · 50,000 shares

Expires not disclosed

F6 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On May 8, 2024, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 50,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 50,000 Paired Interests.

F6 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · ownership.direct: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-24-000057 · wk-form4_1715380692.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 23,898

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 20, 2023.

F5 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $59.0850 to $59.8800 per share. The reporting person will provide to the Issuer, or the Securities and Exchange Commission staff, upon request, information regarding the number of shares sold at each price within the range.

F3 · balance_after: Includes 23,898 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vests on March 11, 2025, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 10, 2023 vests in two equal installments on March 10, 2025 and March 10, 2026, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 7, 2024 vests in three equal installments on March 7, 2025, March 7, 2026 and March 7, 2027, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-24-000057 · wk-form4_1715380692.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 73,898

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: On May 8, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 50,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F2 · shares: On May 8, 2024, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 50,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 50,000 Paired Interests.

F3 · balance_after: Includes 23,898 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vests on March 11, 2025, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 10, 2023 vests in two equal installments on March 10, 2025 and March 10, 2026, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 7, 2024 vests in three equal installments on March 7, 2025, March 7, 2026 and March 7, 2027, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-24-000042 · wk-form4_1712783015.xml · derivative · entry 5

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 50,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F1 · kind: On April 8, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 50,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F1 · shares: On April 8, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 50,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-24-000042 · wk-form4_1712783015.xml · derivative · entry 4

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 50,000

Underlying: Class A Common Stock · 50,000 shares

Expires not disclosed

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On April 8, 2024, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 50,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 50,000 Paired Interests.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001856525-24-000042 · wk-form4_1712783015.xml · derivative · entry 3

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 866,250

Underlying: Class A Common Stock · 50,000 shares

Expires not disclosed

F6 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On April 8, 2024, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 50,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 50,000 Paired Interests.

F6 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · ownership.direct: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-24-000042 · wk-form4_1712783015.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 23,898

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 20, 2023.

F5 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $58.0700 to $59.4400 per share. The reporting person will provide to the Issuer, or the Securities and Exchange Commission staff, upon request, information regarding the number of shares sold at each price within the range.

F3 · balance_after: Includes 23,898 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vests on March 11, 2025, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 10, 2023 vests in two equal installments on March 10, 2025 and March 10, 2026, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 7, 2024 vests in three equal installments on March 7, 2025, March 7, 2026 and March 7, 2027, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-24-000042 · wk-form4_1712783015.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 73,898

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: On April 8, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 50,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F2 · shares: On April 8, 2024, pursuant to the terms of the Fourth Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 50,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 50,000 Paired Interests.

F3 · balance_after: Includes 23,898 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vests on March 11, 2025, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 10, 2023 vests in two equal installments on March 10, 2025 and March 10, 2026, subject to the terms of the associated Participant Restricted Stock Unit Agreement. The unvested portion of the RSUs granted on March 7, 2024 vests in three equal installments on March 7, 2025, March 7, 2026 and March 7, 2027, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-25-000019 · wk-form4_1737151214.xml · nonDerivative · entry 3

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 20,916

F1 · kind: Represents prior share forfeitures to the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units ("RSUs") granted to the reporting person.

F2 · balance_after: Of the 23,898 RSUs originally granted an aggregate of 2,982 shares of Class A common stock have been forfeited to the Issuer for tax withholdings purposes and an aggregate of 6,609 shares of Class A common stock have vested with 14,307 RSUs remaining unvested, as of the date of this Form 4. Each RSU represents a contingent right to receive one share of Class A common stock. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vest on March 11, 2025. The RSUs granted on March 10, 2023 vest in two equal installments on March 10, 2025 and March 10, 2026. The RSUs granted on March 7, 2024 vest in three equal installments on March 7, 2025, March 7, 2026 and March 7, 2027. All RSU vesting is subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-25-000019 · wk-form4_1737151214.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 21,845

F1 · kind: Represents prior share forfeitures to the Issuer for tax withholding purposes upon the vesting of a portion of restricted stock units ("RSUs") granted to the reporting person.

F2 · balance_after: Of the 23,898 RSUs originally granted an aggregate of 2,982 shares of Class A common stock have been forfeited to the Issuer for tax withholdings purposes and an aggregate of 6,609 shares of Class A common stock have vested with 14,307 RSUs remaining unvested, as of the date of this Form 4. Each RSU represents a contingent right to receive one share of Class A common stock. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vest on March 11, 2025. The RSUs granted on March 10, 2023 vest in two equal installments on March 10, 2025 and March 10, 2026. The RSUs granted on March 7, 2024 vest in three equal installments on March 7, 2025, March 7, 2026 and March 7, 2027. All RSU vesting is subject to the terms of the associated Participant Restricted Stock Unit Agreement.

SEC source: 0001856525-24-000028 · wk-form4_1710205903.xml · derivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,726

Underlying: Class A Common Stock · 36,726 shares

Expires 2034-03-07

F3 · derivative.exercise_date: The options vest in three equal installments on March 7, 2025, March 7, 2026 and March 7, 2027, subject to the terms of the associated Participant Stock Option Agreement.

SEC source: 0001856525-24-000028 · wk-form4_1710205903.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,898

F1 · shares: Represents restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock of the Issuer. The RSUs vest in three equal annual installments on March 7, 2025, March 7, 2026 and March 7, 2027, subject to the terms of the associated Participant Restricted Stock Unit Agreement.

F2 · balance_after: Includes RSUs previously granted to the reporting person.

SEC source: 0001209191-23-055812 · doc4.xml · derivative · entry 5

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 40,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F1 · kind: On November 15, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 40,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F1 · shares: On November 15, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 40,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001209191-23-055812 · doc4.xml · derivative · entry 4

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 40,000

Underlying: Class A Common Stock · 40,000 shares

Expires not disclosed

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On November 15, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 40,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 40,000 Paired Interests.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001209191-23-055812 · doc4.xml · derivative · entry 3

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 916,250

Underlying: Class A Common Stock · 40,000 shares

Expires not disclosed

F6 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On November 15, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 40,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 40,000 Paired Interests.

F6 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · ownership.direct: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

SEC source: 0001209191-23-055812 · doc4.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 19,221

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 21, 2023.

F5 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $34.0000 to $34.0550 per share. The reporting person will provide to the Issuer, or the Securities and Exchange Commission staff, upon request, information regarding the number of shares sold at each price within the range.

F3 · balance_after: Includes 19,221 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vest in two equal installments on March 11, 2024 and March 11, 2025, subject to the reporting person remaining employed with the Issuer through each vesting date. The RSUs granted on March 10, 2023 vest in three equal installments on March 10, 2024, March 10, 2025 and March 10, 2026, subject to the reporting person remaining employed with the Issuer through each vesting date.

SEC source: 0001209191-23-055812 · doc4.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 59,221

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: On November 15, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 40,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F2 · shares: On November 15, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 40,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 40,000 Paired Interests.

F3 · balance_after: Includes 19,221 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vest in two equal installments on March 11, 2024 and March 11, 2025, subject to the reporting person remaining employed with the Issuer through each vesting date. The RSUs granted on March 10, 2023 vest in three equal installments on March 10, 2024, March 10, 2025 and March 10, 2026, subject to the reporting person remaining employed with the Issuer through each vesting date.

SEC source: 0001209191-23-055053 · doc4.xml · derivative · entry 5

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 20,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F1 · kind: On November 9, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 20,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F1 · shares: On November 9, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 20,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001209191-23-055053 · doc4.xml · derivative · entry 4

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 20,000

Underlying: Class A Common Stock · 20,000 shares

Expires not disclosed

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On November 9, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 20,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 20,000 Paired Interests.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001209191-23-055053 · doc4.xml · derivative · entry 3

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 956,250

Underlying: Class A Common Stock · 20,000 shares

Expires not disclosed

F6 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On November 9, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 20,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 20,000 Paired Interests.

F6 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · ownership.direct: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

SEC source: 0001209191-23-055053 · doc4.xml · nonDerivative · entry 2

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 19,221

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 21, 2023.

F5 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $32.0000 to $32.3600 per share. The reporting person will provide to the Issuer, or the Securities and Exchange Commission staff, upon request, information regarding the number of shares sold at each price within the range.

F3 · balance_after: Includes 19,221 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vest in two equal installments on March 11, 2024 and March 11, 2025, subject to the reporting person remaining employed with the Issuer through each vesting date. The RSUs granted on March 10, 2023 vest in three equal installments on March 10, 2024, March 10, 2025 and March 10, 2026, subject to the reporting person remaining employed with the Issuer through each vesting date.

SEC source: 0001209191-23-055053 · doc4.xml · nonDerivative · entry 1

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 39,221

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: On November 9, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 20,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F2 · shares: On November 9, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 20,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 20,000 Paired Interests.

F3 · balance_after: Includes 19,221 restricted stock units ("RSUs") granted to the reporting person. Each RSU represents a contingent right to receive one share of Class A common stock. The unvested portion of the RSUs granted on March 11, 2022 vest in two equal installments on March 11, 2024 and March 11, 2025, subject to the reporting person remaining employed with the Issuer through each vesting date. The RSUs granted on March 10, 2023 vest in three equal installments on March 10, 2024, March 10, 2025 and March 10, 2026, subject to the reporting person remaining employed with the Issuer through each vesting date.

SEC source: 0001209191-23-052357 · doc4.xml · derivative · entry 5

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 20,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F1 · kind: On October 4, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 20,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F1 · shares: On October 4, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 20,000 shares of Class B common stock of the Issuer ("Class B common stock") and limited partnership interests of Core & Main Holdings, LP (together, a "Paired Interest") were exchanged for shares of Class A common stock of the Issuer ("Class A common stock"), on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001209191-23-052357 · doc4.xml · derivative · entry 4

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 20,000

Underlying: Class A Common Stock · 20,000 shares

Expires not disclosed

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On October 4, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 20,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 20,000 Paired Interests.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

SEC source: 0001209191-23-052357 · doc4.xml · derivative · entry 3

Witkowski Mark R · CIK 0001866738 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 976,250

Underlying: Class A Common Stock · 20,000 shares

Expires not disclosed

F6 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_price: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F2 · shares: On October 4, 2023, pursuant to the terms of the Third Amended and Restated LLC Agreement of Core & Main Management Feeder, LLC ("Management Feeder"), dated as of July 22, 2021 (as amended, the "LLC Agreement"), 20,000 vested common units ("Units") held directly by the reporting person were redeemed at the discretion of the reporting person for 20,000 Paired Interests.

F6 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.exercise_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.

F7 · derivative.expiration_date: Pursuant to the terms of the Exchange Agreement, Paired Interests are exchangeable at the discretion of the reporting person for shares of Class A common stock on a one-for-one basis or, at the election of a majority of the disinterested members of the Issuer's board of directors, for cash from a substantially concurrent public offering or private sale (based on the price of Class A common stock sold in such public offering or private sale, net of any underwriting discounts and commissions, for each limited partnership interest exchanged, subject to certain exceptions, conditions and adjustments). The Class B common stock and limited partnership interests have no expiration date.

F6 · ownership.direct: Represents securities held by Management Feeder in respect of Units directly held by the reporting person. Pursuant to the LLC Agreement, such vested Units held by the reporting person are redeemable at the discretion of the reporting person for Paired Interests, on a one-for-one basis.