Significant Accounting Policies	3 Months Ended
Mar. 31, 2026
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation References in these financial statements to the Company refer collectively to the accounts of Limbach Holdings, Inc. and its wholly-owned subsidiaries, including Limbach Holdings LLC (“LHLLC”), Limbach Facility Services LLC (“LFS”), Limbach Company LLC (“LC LLC”), Limbach Company LP (“LC LP”), Harper Limbach LLC (“Harper”), Harper Limbach Construction LLC (“Harper Construction LLC”), Limbach Facility & Project Solutions LLC (“LFPS”), Jake Marshall, LLC (“JMLLC”), Coating Solutions, LLC (“CSLLC”), ACME Industrial Piping, LLC (“ACME”), Industrial Air, LLC (“Industrial Air”), Kent Island Mechanical, LLC (“Kent Island”), Consolidated Mechanical, LLC (“Consolidated Mechanical”) and Pioneer Power, LLC (“Pioneer Power”) for all periods presented, unless otherwise indicated. All intercompany balances and transactions have been eliminated. The accompanying unaudited condensed consolidated financial statements were prepared using generally accepted accounting principles (“GAAP”) for interim financial information and with the requirements of Form 10-Q and applicable rules of Regulation S-X of the Securities and Exchange Commission (“SEC”). Consequently, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. Readers of this report should refer to the consolidated financial statements and the notes thereto included in the Company's most recent Annual Report on Form 10-K filed with the SEC on March 2, 2026. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements for assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, the reported amounts of revenue and expenses during the reported period, and the accompanying notes. Management believes that its most significant estimates and assumptions have been based on reasonable and supportable assumptions and the resulting estimates are reasonable for use in the preparation of the condensed consolidated financial statements. The Company’s significant estimates include estimates associated with revenue recognition on construction contracts, costs incurred through each balance sheet date, intangibles, property and equipment, fair value accounting for acquisitions, insurance reserves, income tax valuation allowances, fair value of contingent consideration arrangements and contingencies. If the underlying estimates and assumptions upon which the condensed consolidated financial statements are based change in the future, actual amounts may differ from those included in the accompanying condensed consolidated financial statements. Unaudited Interim Financial Information The accompanying interim Condensed Consolidated Balance Sheets, Condensed Consolidated Statements of Operations, Condensed Consolidated Statements of Stockholders’ Equity and Condensed Consolidated Statements of Cash Flows for the periods presented are unaudited. Also, within the notes to the condensed consolidated financial statements, the Company has included unaudited information for these interim periods. These unaudited interim condensed consolidated financial statements have been prepared in accordance with GAAP. In the Company's opinion, the accompanying unaudited condensed consolidated financial statements contain all normal and recurring adjustments necessary for a fair statement of the Company’s financial position as of March 31, 2026, its results of operations and equity for the three months ended March 31, 2026 and 2025 and its cash flows for the three months ended March 31, 2026 and 2025. The results for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026. The Condensed Consolidated Balance Sheet as of December 31, 2025 was derived from the Company's audited financial statements included in its Annual Report on Form 10-K filed with the SEC on March 2, 2026, but is presented as condensed and does not contain all of the footnote disclosures from the annual financial statements. Recent Accounting Pronouncements In July 2025, the FASB issued ASU 2025-05, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets. ASU 2025-05 provides a practical expedient that all entities can use when estimating expected credit losses for current accounts receivable and current contract assets arising from transactions accounted for under ASC 606, Revenue from Contracts with Customers. Under this practical expedient, an entity is allowed to assume that the current conditions it has applied in determining credit loss allowances for current accounts receivable and current contract assets remain unchanged for the remaining life of those assets. The Company adopted ASU 2025-05 effective January 1, 2026 on a prospective basis and elected to apply the practical expedient to its current accounts receivable and contract assets. The adoption of ASU 2025-05 did not have a material impact on the Company’s condensed consolidated financial statements or related disclosures. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, and in January 2025, the FASB issued ASU 2025-01, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date. ASU 2024-03 requires additional disclosure of the nature of expenses included in the income statement as well as disclosures about specific types of expenses included in the expense captions presented in the income statement. ASU 2024-03, as clarified by ASU 2025-01, is effective for fiscal years beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Companies have the option to apply this guidance either on a retrospective or prospective basis, and early adoption is permitted. The Company is currently evaluating the impact that the adoption of these standards will have on its condensed consolidated financial statements and disclosures.

References in these financial statements to the Company refer collectively to the accounts of Limbach Holdings, Inc. and its wholly-owned subsidiaries, including Limbach Holdings LLC (“LHLLC”), Limbach Facility Services LLC (“LFS”), Limbach Company LLC (“LC LLC”), Limbach Company LP (“LC LP”), Harper Limbach LLC (“Harper”), Harper Limbach Construction LLC (“Harper Construction LLC”), Limbach Facility & Project Solutions LLC (“LFPS”), Jake Marshall, LLC (“JMLLC”), Coating Solutions, LLC (“CSLLC”), ACME Industrial Piping, LLC (“ACME”), Industrial Air, LLC (“Industrial Air”), Kent Island Mechanical, LLC (“Kent Island”), Consolidated Mechanical, LLC (“Consolidated Mechanical”) and Pioneer Power, LLC (“Pioneer Power”) for all periods presented, unless otherwise indicated. All intercompany balances and transactions have been eliminated.

The accompanying unaudited condensed consolidated financial statements were prepared using generally accepted accounting principles (“GAAP”) for interim financial information and with the requirements of Form 10-Q and applicable rules of Regulation S-X of the Securities and Exchange Commission (“SEC”). Consequently, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. Readers of this report should refer to the consolidated financial statements and the notes thereto included in the Company's most recent Annual Report on Form 10-K filed with the SEC on March 2, 2026.

The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements for assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, the reported amounts of revenue and expenses during the reported period, and the accompanying notes. Management believes that its most significant estimates and assumptions have been based on reasonable and supportable assumptions and the resulting estimates are reasonable for use in the preparation of the condensed consolidated financial statements. The Company’s significant estimates include estimates associated with revenue recognition on construction contracts, costs incurred through each balance sheet date, intangibles, property and equipment, fair value accounting for acquisitions, insurance reserves, income tax valuation allowances, fair value of contingent consideration arrangements and contingencies. If the underlying estimates and assumptions upon which the condensed consolidated financial statements are based change in the future, actual amounts may differ from those included in the accompanying condensed consolidated financial statements.

The accompanying interim Condensed Consolidated Balance Sheets, Condensed Consolidated Statements of Operations, Condensed Consolidated Statements of Stockholders’ Equity and Condensed Consolidated Statements of Cash Flows for the periods presented are unaudited. Also, within the notes to the condensed consolidated financial statements, the Company has included unaudited information for these interim periods. These unaudited interim condensed consolidated financial statements have been prepared in accordance with GAAP. In the Company's opinion, the accompanying unaudited condensed consolidated financial statements contain all normal and recurring adjustments necessary for a fair statement of the Company’s financial position as of March 31, 2026, its results of operations and equity for the three months ended March 31, 2026 and 2025 and its cash flows for the three months ended March 31, 2026 and 2025. The results for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026.

The Condensed Consolidated Balance Sheet as of December 31, 2025 was derived from the Company's audited financial statements included in its Annual Report on Form 10-K filed with the SEC on March 2, 2026, but is presented as condensed and does not contain all of the footnote disclosures from the annual financial statements.

In July 2025, the FASB issued ASU 2025-05, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets. ASU 2025-05 provides a practical expedient that all entities can use when estimating expected credit losses for current accounts receivable and current contract assets arising from transactions accounted for under ASC 606, Revenue from Contracts with Customers. Under this practical expedient, an entity is allowed to assume that the current conditions it has applied in determining credit loss allowances for current accounts receivable and current contract assets remain unchanged for the remaining life of those assets. The Company adopted ASU 2025-05 effective January 1, 2026 on a prospective basis and elected to apply the practical expedient to its current accounts receivable and contract assets. The adoption of ASU 2025-05 did not have a material impact on the Company’s condensed consolidated financial statements or related disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, and in January 2025, the FASB issued ASU 2025-01, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date. ASU 2024-03 requires additional disclosure of the nature of expenses included in the income statement as well as disclosures about specific types of expenses included in the expense captions presented in the income statement. ASU 2024-03, as clarified by ASU 2025-01, is effective for fiscal years beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Companies have the option to apply this guidance either on a retrospective or prospective basis, and early adoption is permitted. The Company is currently evaluating the impact that the adoption of these standards will have on its condensed consolidated financial statements and disclosures.