Sec Form 4 Filing - Reed Michael James @ Limbach Holdings, Inc. - 2026-05-18

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Reed Michael James 2. Issuer Name and Ticker or Trading Symbol Limbach Holdings, Inc. [ LMB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Operating Officer (Last) (First) (Middle) 5102 W LAUREL STREET, SUITE 700 3. Date of Earliest Transaction (MM/DD/YY) 05/18/2026 (Street) TAMPA, FL33607 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 3,507 ( 1 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Restricted Stock Units ( 2 ) 05/18/2026 A 403 ( 3 ) ( 3 ) Common Stock 403 $ 0 403 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Reed Michael James 5102 W LAUREL STREET, SUITE 700 TAMPA, FL33607 Chief Operating Officer Signatures /s/ Dan Murtha, Attorney-in-fact for Michael J. Reed 05/20/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The amount of common stock includes awards of restricted stock units (each, an "RSU") granted on January 1, 2024, January 1, 2025, May 1, 2025, and January 1, 2026. Each RSU represents a contingent right to receive one share of Limbach Holdings, Inc. (the "Company") common stock, exempt under Rule 16b-3(d)(1) and (3). Each RSU is subject to service-based vesting conditions. The RSUs vest, in the aggregate, as follows: 689 shares on January 1, 2027, 468 shares on January 1, 2028, and 268 shares on January 1, 2029. The amount of common stock does not include performance-based and market-based RSUs, if any, that may be earned by the reporting person but for which the Compensation Committee has not yet determined the achievements of the applicable performance goals. Any such performance-based and market-based RSUs will be reported on a Form 4 within two business days of the date of such determination. ( 2 )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). ( 3 )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.

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