Castellano James G

SEC source: 0001856525-26-000079 · wk-form4_1782345736.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,437

F1 · shares: Represents restricted stock units granted as director compensation. The restricted stock units will vest upon the earlier to occur of the one year anniversary of the grant date or the Issuer's next annual meeting of shareholders to be held in 2027 and be settled in shares of Class A common stock, subject to the reporting person's continued service as a director of the Issuer.

SEC source: 0001856525-25-000154 · wk-form4_1753137767.xml · derivative · entry 6

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

Underlying: Class A Common Stock · 34,674 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 18, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 34,674 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 18, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 34,674 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: 0001856525-25-000154 · wk-form4_1753137767.xml · derivative · entry 5

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 34,674

Underlying: Class A Common Stock · 34,674 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 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"), 34,674 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano Revocable Trust (the "Trust") were redeemed at the discretion of the Trust for 34,674 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: 0001856525-25-000154 · wk-form4_1753137767.xml · derivative · entry 4

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 158,946

Underlying: Class A Common Stock · 34,674 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 held indirectly by the reporting person through the Trust and the James G. Castellano 2021 Family Trust (the "2021 Trust"). Pursuant to the LLC Agreement, such vested Units held by the Trust and the 2021 Trust are redeemable at the discretion of the Trust and the 2021 Trust 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 held indirectly by the reporting person through the Trust and the James G. Castellano 2021 Family Trust (the "2021 Trust"). Pursuant to the LLC Agreement, such vested Units held by the Trust and the 2021 Trust are redeemable at the discretion of the Trust and the 2021 Trust for Paired Interests, on a one-for-one basis.

F2 · shares: On July 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"), 34,674 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano Revocable Trust (the "Trust") were redeemed at the discretion of the Trust for 34,674 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 held indirectly by the reporting person through the Trust and the James G. Castellano 2021 Family Trust (the "2021 Trust"). Pursuant to the LLC Agreement, such vested Units held by the Trust and the 2021 Trust are redeemable at the discretion of the Trust and the 2021 Trust 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 held indirectly by the reporting person through the Trust and the James G. Castellano 2021 Family Trust (the "2021 Trust"). Pursuant to the LLC Agreement, such vested Units held by the Trust and the 2021 Trust are redeemable at the discretion of the Trust and the 2021 Trust for Paired Interests, on a one-for-one basis.

F7 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust and the James G. Castellano 2021 Family Trust (the "2021 Trust"). Pursuant to the LLC Agreement, such vested Units held by the Trust and the 2021 Trust are redeemable at the discretion of the Trust and the 2021 Trust for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-25-000154 · wk-form4_1753137767.xml · nonDerivative · entry 2

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Trust on April 18, 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 $61.6550 to $62.1950 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 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-25-000154 · wk-form4_1753137767.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 43,994

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 18, 2025, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 34,674 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 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"), 34,674 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano Revocable Trust (the "Trust") were redeemed at the discretion of the Trust for 34,674 Paired Interests.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-25-000141 · wk-form4_1750969791.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,638

F1 · shares: Represents restricted stock units granted as director compensation. The restricted stock units will vest upon the earlier to occur of the one year anniversary of the grant date or the Issuer's next annual meeting of shareholders to be held in 2026 and be settled in shares of Class A common stock, subject to the reporting person's continued service as a director of the Issuer.

SEC source: 0001856525-25-000092 · wk-form4_1745269494.xml · nonDerivative · entry 2

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Trust

Disclosed balance after: 9,320

F1 · shares: Represents 9,320 restricted stock units granted as director compensation transferred by the reporting person to the James G. Castellano 2021 Family Trust (the "Trust") on April 17, 2025 (the "Effective Date").

F2 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-25-000092 · wk-form4_1745269494.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,449

F1 · shares: Represents 9,320 restricted stock units granted as director compensation transferred by the reporting person to the James G. Castellano 2021 Family Trust (the "Trust") on April 17, 2025 (the "Effective Date").

SEC source: 0001856525-25-000094 · wk-form4a_1745365093.xml · nonDerivative · entry 2

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Trust

Disclosed balance after: 9,320

F1 · shares: Represents 9,320 restricted stock units granted as director compensation transferred by the reporting person to the James G. Castellano Revocable Trust dated November 8, 1988 (the "Trust") on April 17, 2025 (the "Effective Date").

F2 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-25-000094 · wk-form4a_1745365093.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,449

F1 · shares: Represents 9,320 restricted stock units granted as director compensation transferred by the reporting person to the James G. Castellano Revocable Trust dated November 8, 1988 (the "Trust") on April 17, 2025 (the "Effective Date").

SEC source: 0001856525-24-000099 · wk-form4_1721247499.xml · derivative · entry 6

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

Underlying: Class A Common Stock · 12,500 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 July 15, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 12,500 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 15, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 12,500 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: 0001856525-24-000099 · wk-form4_1721247499.xml · derivative · entry 5

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 12,500

Underlying: Class A Common Stock · 12,500 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 July 15, 2024, 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"), 12,500 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 12,500 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: 0001856525-24-000099 · wk-form4_1721247499.xml · derivative · entry 4

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 193,620

Underlying: Class A Common Stock · 12,500 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.

F8 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust 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.

F8 · date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F2 · shares: On July 15, 2024, 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"), 12,500 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 12,500 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.

F8 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust 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.

F8 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F8 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-24-000099 · wk-form4_1721247499.xml · nonDerivative · entry 2

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Trust on March 28, 2024.

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 $52.0000 to $52.3500 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 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-24-000099 · wk-form4_1721247499.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 12,500

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 15, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 12,500 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 15, 2024, 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"), 12,500 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 12,500 Paired Interests.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-24-000097 · wk-form4_1720816669.xml · derivative · entry 11

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

Underlying: Class A Common Stock · 12,300 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.

F10 · 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.

F10 · 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 · kind: On July 11, 2024, pursuant to the terms of the Exchange Agreement, 12,300 Paired Interests were exchanged for shares of Class A common stock, on a one-for-one basis.

F6 · shares: On July 11, 2024, pursuant to the terms of the Exchange Agreement, 12,300 Paired Interests were exchanged for shares of Class A common stock, on a one-for-one basis.

F10 · 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.

F10 · 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: 0001856525-24-000097 · wk-form4_1720816669.xml · derivative · entry 10

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 12,300

Underlying: Class A Common Stock · 12,300 shares

Expires not disclosed

F10 · 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.

F10 · 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 · shares: On July 11, 2024, pursuant to the terms of the LLC Agreement, 12,300 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 12,300 Paired Interests.

F10 · 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.

F10 · 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: 0001856525-24-000097 · wk-form4_1720816669.xml · derivative · entry 9

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 206,120

Underlying: Class A Common Stock · 12,300 shares

Expires not disclosed

F10 · 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.

F11 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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.

F11 · date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F7 · shares: On July 11, 2024, pursuant to the terms of the LLC Agreement, 12,300 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 12,300 Paired Interests.

F10 · 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.

F11 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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.

F11 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-24-000097 · wk-form4_1720816669.xml · nonDerivative · entry 4

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Trust on March 28, 2024.

F8 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $50.0500 to $51.1600 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 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-24-000097 · wk-form4_1720816669.xml · nonDerivative · entry 3

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 12,300

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 · kind: On July 11, 2024, pursuant to the terms of the Exchange Agreement, 12,300 Paired Interests were exchanged for shares of Class A common stock, on a one-for-one basis.

F7 · shares: On July 11, 2024, pursuant to the terms of the LLC Agreement, 12,300 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 12,300 Paired Interests.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-24-000097 · wk-form4_1720816669.xml · derivative · entry 8

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

Underlying: Class A Common Stock · 200 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.

F10 · 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.

F10 · 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 10, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 200 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 10, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 200 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.

F10 · 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.

F10 · 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: 0001856525-24-000097 · wk-form4_1720816669.xml · derivative · entry 7

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 200

Underlying: Class A Common Stock · 200 shares

Expires not disclosed

F10 · 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.

F10 · 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 10, 2024, 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"), 200 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 200 Paired Interests.

F10 · 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.

F10 · 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: 0001856525-24-000097 · wk-form4_1720816669.xml · derivative · entry 6

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 218,420

Underlying: Class A Common Stock · 200 shares

Expires not disclosed

F10 · 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.

F11 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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.

F11 · date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F2 · shares: On July 10, 2024, 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"), 200 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 200 Paired Interests.

F10 · 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.

F11 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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.

F11 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

SEC source: 0001856525-24-000097 · wk-form4_1720816669.xml · nonDerivative · entry 2

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Trust on March 28, 2024.

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 $50.0000 to $50.0200 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 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-24-000097 · wk-form4_1720816669.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 200

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 10, 2024, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 200 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 10, 2024, 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"), 200 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 200 Paired Interests.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001856525-24-000085 · wk-form4_1719609748.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,769

F1 · shares: Represents restricted stock units granted as director compensation. The restricted stock units will vest upon the earlier to occur of the one year anniversary of the grant date or the Issuer's next annual meeting of shareholders to be held in 2025 and be settled in shares of Class A common stock, subject to the reporting person's continued service as a director of the Issuer.

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

SEC source: 0001209191-23-054049 · doc4.xml · derivative · entry 11

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

Underlying: Class A Common Stock · 9,890 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.

F11 · 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.

F11 · 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 · kind: On October 31, 2023, pursuant to the terms of the Exchange Agreement, 9,890 Paired Interests were exchanged for shares of Class A common stock, on a one-for-one basis.

F6 · shares: On October 31, 2023, pursuant to the terms of the Exchange Agreement, 9,890 Paired Interests were exchanged for shares of Class A common stock, on a one-for-one basis.

F11 · 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.

F11 · 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: 0001209191-23-054049 · doc4.xml · derivative · entry 10

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 9,890

Underlying: Class A Common Stock · 9,890 shares

Expires not disclosed

F11 · 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.

F11 · 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 · shares: On October 31, 2023, pursuant to the terms of the LLC Agreement, 9,890 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 9,890 Paired Interests.

F11 · 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.

F11 · 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: 0001209191-23-054049 · doc4.xml · derivative · entry 9

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 218,620

Underlying: Class A Common Stock · 9,890 shares

Expires not disclosed

F10 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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.

F10 · date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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 · shares: On October 31, 2023, pursuant to the terms of the LLC Agreement, 9,890 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 9,890 Paired Interests.

F10 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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.

F10 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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.

F10 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

SEC source: 0001209191-23-054049 · doc4.xml · nonDerivative · entry 4

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Trust on June 26, 2023.

F8 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $30.0000 to $30.1050 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 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-054049 · doc4.xml · nonDerivative · entry 3

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 9,890

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 · kind: On October 31, 2023, pursuant to the terms of the Exchange Agreement, 9,890 Paired Interests were exchanged for shares of Class A common stock, on a one-for-one basis.

F7 · shares: On October 31, 2023, pursuant to the terms of the LLC Agreement, 9,890 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 9,890 Paired Interests.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-054049 · doc4.xml · derivative · entry 8

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

Underlying: Class A Common Stock · 2,610 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.

F11 · 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.

F11 · 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 30, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 2,610 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 30, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 2,610 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.

F11 · 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.

F11 · 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: 0001209191-23-054049 · doc4.xml · derivative · entry 7

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 2,610

Underlying: Class A Common Stock · 2,610 shares

Expires not disclosed

F11 · 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.

F11 · 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 30, 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"), 2,610 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 2,610 Paired Interests.

F11 · 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.

F11 · 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: 0001209191-23-054049 · doc4.xml · derivative · entry 6

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 228,510

Underlying: Class A Common Stock · 2,610 shares

Expires not disclosed

F10 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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.

F10 · date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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 30, 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"), 2,610 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 2,610 Paired Interests.

F10 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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.

F10 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F11 · 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.

F10 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

SEC source: 0001209191-23-054049 · doc4.xml · nonDerivative · entry 2

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

F4 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Trust on June 26, 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 $30.0000 to $30.0100 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 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-054049 · doc4.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 2,610

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 October 30, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 2,610 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 October 30, 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"), 2,610 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 2,610 Paired Interests.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-050700 · doc4.xml · derivative · entry 8

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

Underlying: Class A Common Stock · 12,358 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.

F10 · 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 Issuers 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.

F10 · 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 Issuers 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.

F4 · kind: On September 25, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 12,358 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, on a one-for-one basis.

F4 · shares: On September 25, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 12,358 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, on a one-for-one basis.

F10 · 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 Issuers 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.

F10 · 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 Issuers 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.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-050700 · doc4.xml · derivative · entry 7

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 12,358

Underlying: Class A Common Stock · 12,358 shares

Expires not disclosed

F10 · 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 Issuers 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.

F10 · 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 Issuers 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 · shares: On September 25, 2023, pursuant to the terms of the LLC Agreement, 12,358 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 12,358 Paired Interests.

F10 · 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 Issuers 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.

F10 · 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 Issuers 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.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-050700 · doc4.xml · derivative · entry 6

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 231,120

Underlying: Class A Common Stock · 12,358 shares

Expires not disclosed

F9 · derivative.exercise_price: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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 Issuers 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.

F9 · date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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 Issuers 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 · shares: On September 25, 2023, pursuant to the terms of the LLC Agreement, 12,358 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 12,358 Paired Interests.

F9 · derivative.exercise_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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 Issuers 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.

F9 · derivative.expiration_date: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

F10 · 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 Issuers 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.

F9 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for Paired Interests, on a one-for-one basis.

SEC source: 0001209191-23-050700 · doc4.xml · nonDerivative · entry 4

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 0

F6 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Trust on June 26, 2023.

F7 · price: The price reported represents the weighted average price of shares of Class A common stock sold in multiple transactions at prices ranging from $28.3000 to $28.4800 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 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-050700 · doc4.xml · nonDerivative · entry 3

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 12,500

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.

F4 · kind: On September 25, 2023, pursuant to the terms of an exchange agreement, dated as of July 22, 2021 (as amended, the "Exchange Agreement"), 12,358 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, on a one-for-one basis.

F5 · shares: On September 25, 2023, pursuant to the terms of the LLC Agreement, 12,358 vested Units held indirectly by the reporting person through the Trust were redeemed at the discretion of the Trust for 12,358 Paired Interests.

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-050700 · doc4.xml · nonDerivative · entry 2

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Trust

Disclosed balance after: 142

F1 · shares: On September 25, 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"), 142 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 142 shares of Class A common stock of the Issuer ("Class A common stock").

F3 · ownership.direct: Represents securities held indirectly by the reporting person through the Trust.

SEC source: 0001209191-23-050700 · doc4.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By LLC

Disclosed balance after: 0

F1 · shares: On September 25, 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"), 142 vested common units ("Units") held indirectly by the reporting person through the James G. Castellano 2021 Family Trust (the "Trust") were redeemed at the discretion of the Trust for 142 shares of Class A common stock of the Issuer ("Class A common stock").

F2 · ownership.direct: Represents securities held by Management Feeder in respect of Units held indirectly by the reporting person through the Trust. Pursuant to the LLC Agreement, such vested Units held by the Trust are redeemable at the discretion of the Trust for shares of Class A common stock, on a one-for-one basis.

SEC source: 0001209191-23-040308 · doc4.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,320

F1 · shares: Represents restricted stock units granted as director compensation. The restricted stock units will vest upon the earlier to occur of the one year anniversary of the grant date or the Issuer's next annual meeting of stockholders to be held in 2024 and be settled in shares of Class A common stock, subject to the reporting person's continued service as a director of the Issuer.

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

SEC source: 0001209191-23-018945 · doc5.xml · nonDerivative · entry 1

Castellano James G · CIK 0001866541 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,393

F1 · shares: Represents restricted stock units granted as director compensation. The restricted stock units will vest upon the earlier to occur of the one year anniversary of the grant date or the Issuer's next annual meeting of stockholders to be held in 2023 and be settled in shares of Class A common stock, subject to the reporting person's continued service as a director of the Issuer.