LMB

SEC source: 0001628280-26-062492 · wk-form4_1789675631.xml · nonDerivative · entry 1

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 67,642

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2026 by the reporting person.

SEC source: 0001628280-26-062237 · wk-form4_1789589054.xml · nonDerivative · entry 1

Krzeminski Laurel J · CIK 0001493187 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By SEP-IRA

Disclosed balance after: 4,000

F1 · balance_after: The ownership amounts reported herein reflect the separate presentation of shares held through the Reporting Person's SEP IRA, shares held jointly with the Reporting Person's spouse and shares held by the Laurel J. Krzeminski Revocable Trust, of which the Reporting Person is the settlor and a co-trustee. Prior reports presented these holdings in the aggregate as directly owned. This reclassification does not reflect an acquisition or disposition of securities or change in the Reporting Person's aggregate beneficial ownership. The 500-share purchase reported herein is included in the SEP IRA balance.

SEC source: 0001104659-26-108006 · tm2625504-1_4seq1.xml · nonDerivative · entry 5

Horowitz Joshua · CIK 0001612424 · Director

Palm Global Small Cap Master Fund LP · CIK 0001726444 · Director Affiliate

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · Palm Global Small Cap Master Fund LP

Disclosed balance after: 171,208

F1 · ownership.nature: Palm Management (US) LLC, as the investment manager of Palm Global Small Cap Master Fund LP ("Palm Global"), may be deemed to be a beneficial owner of the shares of common stock disclosed as directly owned by Palm Global. Due to his positions as a portfolio manager and special limited partner of Palm Global and as an employee of Palm Management (US) LLC, Mr. Horowitz may be deemed to be a beneficial owner of the shares of common stock disclosed as directly owned by Palm Global. Palm Management (US) LLC and Mr. Horowitz expressly disclaim such beneficial ownership except to the extent of their pecuniary interest therein.

SEC source: 0001104659-26-108006 · tm2625504-1_4seq1.xml · nonDerivative · entry 4

Horowitz Joshua · CIK 0001612424 · Director

Palm Global Small Cap Master Fund LP · CIK 0001726444 · Director Affiliate

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · Palm Global Small Cap Master Fund LP

Disclosed balance after: 170,546

F3 · price: The price reported represents a weighted average price. These shares were purchased in multiple transactions at prices ranging from $50.21 to $51.17 per share. The Reporting Persons undertake to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price.

F1 · ownership.nature: Palm Management (US) LLC, as the investment manager of Palm Global Small Cap Master Fund LP ("Palm Global"), may be deemed to be a beneficial owner of the shares of common stock disclosed as directly owned by Palm Global. Due to his positions as a portfolio manager and special limited partner of Palm Global and as an employee of Palm Management (US) LLC, Mr. Horowitz may be deemed to be a beneficial owner of the shares of common stock disclosed as directly owned by Palm Global. Palm Management (US) LLC and Mr. Horowitz expressly disclaim such beneficial ownership except to the extent of their pecuniary interest therein.

SEC source: 0001104659-26-108006 · tm2625504-1_4seq1.xml · nonDerivative · entry 3

Horowitz Joshua · CIK 0001612424 · Director

Palm Global Small Cap Master Fund LP · CIK 0001726444 · Director Affiliate

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 43,997

SEC source: 0001628280-26-062236 · wk-form4_1789589048.xml · nonDerivative · entry 1

Gaboury David Richard · CIK 0002026309 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,193

SEC source: 0001104659-26-108006 · tm2625504-1_4seq1.xml · nonDerivative · entry 2

Horowitz Joshua · CIK 0001612424 · Director

Palm Global Small Cap Master Fund LP · CIK 0001726444 · Director Affiliate

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · Palm Global Small Cap Master Fund LP

Disclosed balance after: 167,200

F2 · price: The price reported represents a weighted average price. These shares were purchased in multiple transactions at prices ranging from $48.88 to $49.745 per share. The Reporting Persons undertake to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price.

F1 · ownership.nature: Palm Management (US) LLC, as the investment manager of Palm Global Small Cap Master Fund LP ("Palm Global"), may be deemed to be a beneficial owner of the shares of common stock disclosed as directly owned by Palm Global. Due to his positions as a portfolio manager and special limited partner of Palm Global and as an employee of Palm Management (US) LLC, Mr. Horowitz may be deemed to be a beneficial owner of the shares of common stock disclosed as directly owned by Palm Global. Palm Management (US) LLC and Mr. Horowitz expressly disclaim such beneficial ownership except to the extent of their pecuniary interest therein.

SEC source: 0001104659-26-108006 · tm2625504-1_4seq1.xml · nonDerivative · entry 1

Horowitz Joshua · CIK 0001612424 · Director

Palm Global Small Cap Master Fund LP · CIK 0001726444 · Director Affiliate

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 43,785

SEC source: 0001628280-26-043880 · wk-form4_1781727048.xml · nonDerivative · entry 5

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 72,736

F5 · shares: Represents a bona fide gift of shares of Limbach Holdings, Inc's. common stock for which no payment or consideration was received by the reporting person.

SEC source: 0001628280-26-043880 · wk-form4_1781727048.xml · nonDerivative · entry 4

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 73,456

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2026 by the reporting person.

SEC source: 0001628280-26-043880 · wk-form4_1781727048.xml · nonDerivative · entry 3

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 73,656

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2026 by the reporting person.

F4 · price: This transaction was executed in multiple trades at prices ranging from $80.07 to $80.84. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-043880 · wk-form4_1781727048.xml · nonDerivative · entry 2

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 75,677

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2026 by the reporting person.

F3 · price: This transaction was executed in multiple trades at prices ranging from $79.05 to $80.04. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-043880 · wk-form4_1781727048.xml · nonDerivative · entry 1

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 77,539

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2026 by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $78.03 to $79.02. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-036912 · wk-form4_1779308536.xml · derivative · entry 2

Reed Michael James · CIK 0002135165 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 403

Underlying: Common Stock · 403 shares

Expires not disclosed

F2 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock and is exempt under Rule 16b-3(d)(1) and (3).

F3 · derivative.exercise_date: This award of RSUs was granted on May 18, 2026. The award is subject to service-based vesting conditions and vests in three annual installments on May 18, 2027, May 18, 2028 and May 18, 2029, with the final installment adjusted to reflect that no fractional shares will be issued, subject to continued employment through each applicable vesting date. The amounts reported above (related to this grant) do not include market-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSUs will be reported on a Form 4 within two business days of the date of such determination.

F3 · derivative.expiration_date: This award of RSUs was granted on May 18, 2026. The award is subject to service-based vesting conditions and vests in three annual installments on May 18, 2027, May 18, 2028 and May 18, 2029, with the final installment adjusted to reflect that no fractional shares will be issued, subject to continued employment through each applicable vesting date. The amounts reported above (related to this grant) do not include market-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSUs will be reported on a Form 4 within two business days of the date of such determination.

SEC source: 0001628280-26-029342 · wk-form4_1777666548.xml · nonDerivative · entry 1

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 125,227

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

SEC source: 0001628280-26-027959 · wk-form4_1777407962.xml · nonDerivative · entry 1

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 128,667

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $100.00 to $100.50. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-025255 · wk-form4_1776283986.xml · nonDerivative · entry 1

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 130,840

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $85.18 to $85.82. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-024769 · wk-form4_1775856634.xml · nonDerivative · entry 2

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 136,543

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F3 · price: This transaction was executed in multiple trades at prices ranging from $85.00 to $85.50. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-024769 · wk-form4_1775856634.xml · nonDerivative · entry 1

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 137,384

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $85.00 to $85.54. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019542 · wk-form4_1773870610.xml · nonDerivative · entry 5

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 140,750

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F6 · price: This transaction was executed in multiple trades at prices ranging from $81.16 to $81.87. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019542 · wk-form4_1773870610.xml · nonDerivative · entry 4

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 141,850

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F5 · price: This transaction was executed in multiple trades at prices ranging from $79.99 to $80.74. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019542 · wk-form4_1773870610.xml · nonDerivative · entry 3

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 143,396

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F4 · price: This transaction was executed in multiple trades at prices ranging from $78.57 to $79.17. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019542 · wk-form4_1773870610.xml · nonDerivative · entry 2

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 143,856

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F3 · price: This transaction was executed in multiple trades at prices ranging from $77.57 to $78.54. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019542 · wk-form4_1773870610.xml · nonDerivative · entry 1

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 148,023

F1 · shares: This transaction is part of a 10b5-1 plan adopted on December 16, 2025 by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $76.57 to $77.56. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019541 · wk-form4_1773870604.xml · nonDerivative · entry 5

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 78,327

F6 · shares: Represents a bona fide gift of shares of Limbach Holdings, Inc's. common stock for which no payment or consideration was received by the reporting person.

SEC source: 0001628280-26-019541 · wk-form4_1773870604.xml · nonDerivative · entry 4

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 79,027

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2025 by the reporting person.

F5 · price: This transaction was executed in multiple trades at prices ranging from $81.30 to $81.72. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019541 · wk-form4_1773870604.xml · nonDerivative · entry 3

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 79,527

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2025 by the reporting person.

F4 · price: This transaction was executed in multiple trades at prices ranging from $80.03 to $80.96. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019541 · wk-form4_1773870604.xml · nonDerivative · entry 2

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 79,827

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2025 by the reporting person.

F3 · price: This transaction was executed in multiple trades at prices ranging from $79.00 to $79.87. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-019541 · wk-form4_1773870604.xml · nonDerivative · entry 1

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 80,536

F1 · shares: This transaction is part of a 10b5-1 plan adopted on March 14, 2025 by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $78.00 to $78.98. The price reported above reflects the weighted average price. The reporting person hereby undertakes to provide to the Company, any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0001628280-26-014724 · wk-form4_1772662453.xml · nonDerivative · entry 2

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 167,514

F2 · shares: Reflects the withholding of 20,466 shares by the Company to satisfy tax withholding requirements. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-014724 · wk-form4_1772662453.xml · nonDerivative · entry 1

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 187,980

F1 · shares: Represents 52,008 shares of Limbach Holdings, Inc. (the "Company") common stock issued to the reporting person on March 2, 2026 upon vesting of 34,672 performance-based restricted stock units, based on the achievement of certain pre-established performance goals at above-target levels for the performance period commencing on January 1, 2023 through December 31, 2025. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-014723 · wk-form4_1772662447.xml · nonDerivative · entry 2

Angerosa Nicholas · CIK 0001965575 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 67,639

F2 · shares: Reflects the withholding of 8,878 shares by the Company to satisfy tax withholding requirements. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-014723 · wk-form4_1772662447.xml · nonDerivative · entry 1

Angerosa Nicholas · CIK 0001965575 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 76,517

F1 · shares: Represents 22,559 shares of Limbach Holdings, Inc. (the "Company") common stock issued to the reporting person on March 2, 2026 upon vesting of 15,040 performance-based restricted stock units, based on the achievement of certain pre-established performance goals at above-target levels for the performance period commencing on January 1, 2023 through December 31, 2025. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-014726 · wk-form4_1772662465.xml · nonDerivative · entry 2

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 81,027

F2 · shares: Reflects the withholding of 12,359 shares by the Company to satisfy tax withholding requirements. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-014726 · wk-form4_1772662465.xml · nonDerivative · entry 1

Sharp Jay · CIK 0001965562 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 93,386

F1 · shares: Represents 28,747 shares of Limbach Holdings, Inc. (the "Company") common stock issued to the reporting person on March 2, 2026 upon vesting of 19,165 performance-based restricted stock units, based on the achievement of certain pre-established performance goals at above-target levels for the performance period commencing on January 1, 2023 through December 31, 2025. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-014725 · wk-form4_1772662459.xml · nonDerivative · entry 2

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 150,660

F2 · shares: Reflects the withholding of 16,070 shares by the Company to satisfy tax withholding requirements. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-014725 · wk-form4_1772662459.xml · nonDerivative · entry 1

Brooks Jayme L. · CIK 0001447591 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 166,730

F1 · shares: Represents 40,835 shares of Limbach Holdings, Inc. (the "Company") common stock issued to the reporting person on March 2, 2026 upon vesting of 27,224 performance-based restricted stock units, based on the achievement of certain pre-established performance goals at above-target levels for the performance period commencing on January 1, 2023 through December 31, 2025. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.

SEC source: 0001628280-26-002872 · wk-form4_1769029703.xml · derivative · entry 1

Dugan Terence Patrick · CIK 0002105879 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,498

Underlying: Common Stock · 1,498 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of Limbach Holdings, Inc. (the "Company") common stock, exempt under Rule 16b-3.

F2 · derivative.exercise_date: This award of RSUs was granted on January 20, 2026. The RSUs are scheduled to cliff vest on January 1, 2027.

F2 · derivative.expiration_date: This award of RSUs was granted on January 20, 2026. The RSUs are scheduled to cliff vest on January 1, 2027.

SEC source: 0001628280-26-000537 · wk-form4_1767649777.xml · derivative · entry 3

ALVARADO LINDA G · CIK 0001122788 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,498

Underlying: Common Stock · 1,498 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of Limbach Holdings, Inc. (the "Company") common stock, exempt under Rule 16b-3.

F3 · derivative.exercise_date: This award of RSUs was granted on January 1, 2026. The RSUs are scheduled to cliff vest on January 1, 2027.

F3 · derivative.expiration_date: This award of RSUs was granted on January 1, 2026. The RSUs are scheduled to cliff vest on January 1, 2027.

SEC source: 0001628280-26-000537 · wk-form4_1767649777.xml · derivative · entry 2

ALVARADO LINDA G · CIK 0001122788 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 956 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.

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of Limbach Holdings, Inc. (the "Company") common stock, exempt under Rule 16b-3.

F2 · derivative.exercise_date: This award of RSUs was granted on January 1, 2025. The RSUs cliff vested on January 1, 2026.

F2 · derivative.expiration_date: This award of RSUs was granted on January 1, 2025. The RSUs cliff vested on January 1, 2026.

SEC source: 0001628280-26-000537 · wk-form4_1767649777.xml · nonDerivative · entry 1

ALVARADO LINDA G · CIK 0001122788 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,160

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.

SEC source: 0001628280-26-000539 · wk-form4_1767649783.xml · derivative · entry 3

Gaboury David Richard · CIK 0002026309 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,498

Underlying: Common Stock · 1,498 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of Limbach Holdings, Inc. (the "Company") common stock, exempt under Rule 16b-3.

F3 · derivative.exercise_date: This award of RSUs was granted on January 1, 2026. The RSUs are scheduled to cliff vest on January 1, 2027.

F3 · derivative.expiration_date: This award of RSUs was granted on January 1, 2026. The RSUs are scheduled to cliff vest on January 1, 2027.

SEC source: 0001628280-26-000539 · wk-form4_1767649783.xml · derivative · entry 2

Gaboury David Richard · CIK 0002026309 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 956 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.

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of Limbach Holdings, Inc. (the "Company") common stock, exempt under Rule 16b-3.

F2 · derivative.exercise_date: This award of RSUs was granted on January 1, 2025. The RSUs cliff vested on January 1, 2026.

F2 · derivative.expiration_date: This award of RSUs was granted on January 1, 2025. The RSUs cliff vested on January 1, 2026.

SEC source: 0001628280-26-000539 · wk-form4_1767649783.xml · nonDerivative · entry 1

Gaboury David Richard · CIK 0002026309 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,253

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.

SEC source: 0001628280-26-000541 · wk-form4_1767649789.xml · derivative · entry 11

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,887

Underlying: Common Stock · 6,260 shares

Expires not disclosed

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock, exempt under Rule 16b-3(d)(1) and (3).

F8 · derivative.exercise_date: This award of RSUs was granted on January 1, 2026. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2027, January 1, 2028 and January 1, 2029, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

F8 · derivative.expiration_date: This award of RSUs was granted on January 1, 2026. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2027, January 1, 2028 and January 1, 2029, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

SEC source: 0001628280-26-000541 · wk-form4_1767649789.xml · derivative · entry 10

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,627

Underlying: Common Stock · 1,499 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.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock, exempt under Rule 16b-3(d)(1) and (3).

F7 · derivative.exercise_date: This award of RSUs was granted on January 1, 2025. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2026, January 1, 2027 and January 1, 2028, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

F7 · derivative.expiration_date: This award of RSUs was granted on January 1, 2025. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2026, January 1, 2027 and January 1, 2028, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

SEC source: 0001628280-26-000541 · wk-form4_1767649789.xml · derivative · entry 9

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,126

Underlying: Common Stock · 2,627 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.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock, exempt under Rule 16b-3(d)(1) and (3).

F6 · derivative.exercise_date: This award of RSUs was granted on January 1, 2024. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2025, January 1, 2026 and January 1, 2027, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

F6 · derivative.expiration_date: This award of RSUs was granted on January 1, 2024. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2025, January 1, 2026 and January 1, 2027, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

SEC source: 0001628280-26-000541 · wk-form4_1767649789.xml · derivative · entry 8

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,753

Underlying: Common Stock · 1,080 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.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock, exempt under Rule 16b-3(d)(1) and (3).

F5 · derivative.exercise_date: This award of RSUs was granted on January 17, 2023. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2024, January 1, 2025 and January 1, 2026, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

F5 · derivative.expiration_date: This award of RSUs was granted on January 17, 2023. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2024, January 1, 2025 and January 1, 2026, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

SEC source: 0001628280-26-000541 · wk-form4_1767649789.xml · derivative · entry 7

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,833

Underlying: Common Stock · 4,699 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.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock, exempt under Rule 16b-3(d)(1) and (3).

F4 · derivative.exercise_date: This award of RSUs was granted on January 4, 2023. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2024, January 1, 2025 and January 1, 2026, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

F4 · derivative.expiration_date: This award of RSUs was granted on January 4, 2023. The award is subject to service-based vesting conditions and vests in equal annual installments on each of January 1, 2024, January 1, 2025 and January 1, 2026, subject to continued employment through the applicable vesting date. The amounts reported above (related to this grant) do not include performance-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievement of the applicable performance goals. Any such RSU's will be reported on a Form 4 within two business days of the date of such determination.

SEC source: 0001628280-26-000541 · wk-form4_1767649789.xml · nonDerivative · entry 5

McCann Michael M · CIK 0001760470 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 135,972

F1 · shares: Reflects the withholding of shares by Limbach Holdings, Inc. (the "Company") to satisfy tax withholding requirements. Such transaction was exempt from Section 16(b) pursuant to Rule 16b-3.