Limbach Holdings, Inc.

Note 1 –Business and Organization

Limbach Holdings, Inc. (the “Company,” “we” or “our”), a Delaware corporation headquartered in Warrendale, Pennsylvania, is a building systems solutions firm that designs, delivers, and maintains mechanical (heating, ventilation, and air conditioning), electrical, plumbing, and controls (“MEPC”) systems. The Company partners with building owners and operators of mission-critical facilities across healthcare, industrial and manufacturing, data centers, life sciences, higher education, and cultural and entertainment markets. With approximately 1,500 employees across 21 offices throughout the Eastern and Midwestern regions of the United States, the Company strives to be an indispensable partner by combining its national capabilities with strong local execution and talent to deliver proactive, safe, and reliable solutions for complex facilities. Operating on a connected platform, the Company integrates engineering expertise with field execution to provide customized MEPC infrastructure solutions that address both operational and capital project needs, optimizing performance, enhancing reliability, and ensuring long-term safety.

The Company operates intwo segments, (i) Owner Direct Relationships (“ODR”), in which the Company performs owner direct projects and/or provides maintenance or service primarily on MEPC systems, and specialty contracting projects to existing buildings direct to, or assigned by, building owners or operators, and (ii) General Contractor Relationships (“GCR”), in which the Company generally manages new construction or renovation projects that involve primarily MEPC systems awarded to the Company by general contractors or construction managers. The Company's work is primarily performed under fixed-price, modified fixed-price, and time and materials contracts over periods of typically less thantwo years.

Note 2 –Significant Accounting Policies

Basis of Presentation

The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) and the rules and regulations of the Securities and Exchange Commission (“SEC”) and based on the assumption that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities in the normal course of business.

Principles of Consolidation

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, Harper Limbach LLC, Harper Limbach Construction LLC, Limbach Facility & Project Solutions LLC, 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.

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the 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 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 consolidated financial statements are based change in the future, actual amounts may differ from those included in the accompanying consolidated financial statements.

Cash and Cash Equivalents

Cash and cash equivalents consist of cash on hand and highly liquid investments with original maturities of three months or less at the date of purchase. Cash and cash equivalents are recorded at cost, which approximates fair value due to the short-term nature of these instruments.

At December 31, 2025, the Company’s cash and cash equivalents consisted primarily of demand deposits with commercial banks and overnight repurchase agreements. At December 31, 2024, cash and cash equivalents also included investments in highly liquid money market funds and U.S. Treasury bills.

From time to time, amounts held in deposit accounts may exceed federally insured limits. The Company mitigates this risk by maintaining deposits with high credit-quality financial institutions and, to date, has not experienced any losses on such balances. See Note 9 – Fair Value Measurements in the accompanying notes to the Company’s consolidated financial statements for further information.

Restricted Cash

Restricted cash is cash held at a commercial bank in an imprest account held for the purpose of funding workers’ compensation and general liability claims against the Company. This amount is replenished either when depleted or at the beginning of each month.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Company’s consolidated balance sheets that sum to the total of the same amounts shown in the consolidated statements of cash flows:

Accounts Receivable and Allowance for Credit Losses

The carrying value of the Company’s receivables, net of the allowance for credit losses, represents their estimated net realizable value. The Company develops its allowance using an aging methodology and evaluates expected losses based on historical loss experience adjusted for current conditions and, when appropriate, reasonable and supportable forecasts. The determination of the allowance requires judgment and estimates involving, among others, the creditworthiness of customers, historical collection experience, the aging of past due balances, the consideration of a customer’s financial condition, ongoing relationships with customers, lien rights (if any), the availability of payment bonds or other security, and broader market and economic conditions. The Company evaluates and updates these estimates as additional information becomes available. When the Company becomes aware of a customer’s inability to meet its financial obligation, a specific reserve is recorded to reduce the receivable to the expected amount to be collected. Balances that are still outstanding after management has used reasonable collection efforts are written off through a charge to the valuation allowance and an adjustment of the account receivable. The majority of customer balances at each balance sheet date are collected within twelve months. As is common practice in the industry, the Company classifies all accounts receivable as current assets. Based on assessments by management, allowances for credit losses were approximately $0.4 million at both December 31, 2025 and 2024.

Joint Ventures

The Company participates in certain special purpose, project-specific joint ventures that are generally formed to bid on, negotiate and perform specific projects. The Company accounts for these investments under the equity method of accounting. Under the joint venture arrangements, the joint venture typically enters into the prime contract with the customer and issues subcontracts to the venturers for each party’s respective scope of work. The Company records revenue, costs, and the related contract assets and liabilities associated with its subcontract in the consolidated financial statements in accordance with its revenue recognition policies, consistent with the accounting for other construction contracts.

The joint venture itself does not accumulate any profits or losses, as the joint venture revenue is equal to the sum of the subcontracts it issues to the joint venture partners. The voting power and management of the joint ventures are shared equally by the joint venture partners, qualifying these entities for joint venture treatment under GAAP. The shared voting power and management responsibilities allow the Company to exercise significant influence without controlling the joint venture entity. As such, the Company applies the equity method of accounting as defined in ASC Topic 323, Investments – Equity Method and Joint Ventures.

Revenue Recognition

The Company’s revenue is primarily derived from construction-type and service contracts that are typically less thantwo years. The Company’s service arrangements generally include (i) fixed-price service contracts, typically for maintenance, repair and retrofit work over a period, commonly one year, and (ii) time and materials or similar service work performed on an as-needed basis. The Company accounts for revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers, which requires revenue to be recognized as control of promised goods or services is transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled.

Contract identification and collectability. A contract with a customer exists when approval and commitment are present, each party’s rights and payment terms are identifiable, the contract has commercial substance, and collectability is probable. Judgment is required in determining whether these criteria are met, including in circumstances where work commences prior to receipt of a formally executed contract. In such cases, the Company evaluates all relevant facts and circumstances, including documentation evidencing the parties’ agreement and historical experience with the customer, in assessing whether an enforceable contract exists. In assessing collectability, the Company considers the customer’s ability and intent to pay, including creditworthiness and payment history.

Performance obligations. At contract inception, the Company evaluates promised goods and services to identify performance obligations. Performance obligations represent the unit of account for revenue recognition. Judgment is applied in determining whether promised goods or services are distinct (i.e., capable of being distinct and distinct within the context of the contract).

Transaction price and variable consideration. The transaction price is the amount of consideration the Company expects to be entitled to in exchange for transferring goods or services to the customer, and may include fixed and variable amounts. Variable consideration may arise from change orders, claims, incentives, penalties, or other contract provisions. The Company estimates variable consideration using either the expected value method or the most likely amount method, depending on which better predicts the amount of consideration expected. Variable consideration is included in the transaction price only to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty is resolved (the “constraint”). In applying the constraint, the Company considers factors such as susceptibility to factors outside its influence, the expected timing of resolution, and the extent of historical experience with similar arrangements.

Pending change orders are a common source of variable consideration and generally represent contract modifications for which the scope has been authorized or acknowledged by the customer, but pricing has not been finalized. In estimating the transaction price related to pending change orders, the Company considers relevant facts and circumstances, including written communications with the customer and historical experience with similar modifications, and applies the constraint as appropriate.

Contract claims may arise when the Company seeks recovery for changes in scope or other causes not yet agreed to by the customer. Given the uncertainty associated with claims, including the timing and outcome of dispute resolution, amounts related to claims are generally more likely to be constrained. Costs to pursue claims, including litigation costs, if incurred, are expensed as incurred.

Measure of progress and recognition of revenue over time. The Company recognizes revenue over time for construction-type contracts when the Company’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or when the asset under construction has no alternative use to the Company and the Company has an enforceable right to payment for performance completed to date. Revenue is recognized based on the Company’s progress toward complete satisfaction of the applicable performance obligations.

The Company generally measures progress for construction-type contracts using a cost-to-cost input method, under which progress is measured by the ratio of costs incurred to date to total estimated costs to complete for each performance obligation. Costs included in the measure of progress generally consist of labor, materials, subcontractor costs, and other direct and indirect costs, including depreciation. Revenue, including estimated profit, is recognized in proportion to progress.

For service-type contracts, revenue is generally recognized over time as the customer simultaneously receives and consumes the benefits of the Company’s performance. For fixed-price service-type contracts with specified service periods, revenue is generally recognized on a straight-line basis over the contract term when the Company’s performance is expected to be expended evenly and the customer receives and consumes benefits throughout the term.

Retainage and significant financing components. Certain contracts include retainage provisions intended to provide customers assurance of performance; retainage is not considered a significant financing component. Amounts billed but not yet paid pursuant to retainage provisions generally become due upon completion and acceptance of the project work. The Company determined that its contracts did not include significant financing components for the years ended December 31, 2025 and 2024.

Changes in estimates and loss provisions. Due to uncertainties inherent in the estimation process, the Company’s estimates of total costs to complete a performance obligation may change. For performance obligations recognized using the cost-to-cost method, changes in estimated total costs are reflected through a cumulative catch-up adjustment in the period the change is identified. When current estimates indicate a loss on a performance obligation, the Company recognizes a provision for the full amount of the expected loss in the period such loss becomes evident.

Contract costs. Costs incurred to fulfill contracts that are not expected to be recoverable from the customer (including certain pre-bid costs) are expensed as incurred and included in selling, general and administrative expenses.

In accordance with industry practice, the Company classifies as current all assets and liabilities relating to the performance of contracts. See Note 4 – Revenue from Contracts with Customers in the accompanying notes to the Company’s consolidated financial statements for further information.

Changes in Estimates on Construction Contracts

The accuracy of revenue and profit recognized depends on estimates of total costs to complete each project. Changes in estimates may result from, among other factors, bid accuracy, scope changes and change order resolution, claims and dispute outcomes, labor and material cost fluctuations, productivity and subcontractor performance, project delays (including owner- or weather-related delays), differing site conditions, design changes on design-build projects, and customer administration of the contract.

After contract inception, the transaction price may change due to change orders, contract modifications, incentives, penalties, and claims. Contract modifications are evaluated to determine whether they should be accounted for as part of the existing performance obligation(s) or as separate performance obligation(s), and the transaction price is allocated accordingly. Pending change orders and affirmative claims are included in the transaction price only when the amount can be reasonably estimated and it is probable that including such amounts will not result in a significant reversal of revenue.

Goodwill and Impairment of Long-Lived Assets

Goodwill is evaluated for impairment at least annually and more frequently if events or changes in circumstances indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. The Company may first perform a qualitative assessment to determine whether a quantitative impairment test is necessary or may elect to proceed directly to a quantitative impairment test.

Under the qualitative assessment, the Company evaluates relevant events and circumstances to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after considering the totality of these factors, the Company concludes that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, no further testing is required. If the Company is unable to reach this conclusion, a quantitative impairment test is performed.

In a quantitative impairment test, the Company estimates the fair value of the applicable reporting unit and compares it to its carrying amount. If the fair value of a reporting unit is less than its carrying amount, an impairment charge is recognized for the difference, limited to the amount of goodwill allocated to that reporting unit. See Note 5 – Goodwill and Intangible Assets for further detail.

The Company evaluates long-lived assets, including property, plant and equipment and finite-lived intangible assets, for impairment whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. Recoverability is assessed at the asset group level by comparing the carrying amount of the asset group to the sum of the expected future undiscounted cash flows. These estimates require management to make assumptions regarding, among other factors, expected revenue and margin trends, demand, pricing, competition, operating costs and other market conditions. If the carrying amount of an asset group exceeds its expected future undiscounted cash flows, the Company recognizes an impairment loss equal to the amount by which the carrying amount exceeds fair value. Fair value is determined using quoted market prices when available or, if not available, valuation techniques such as discounted cash flow analyses. Changes in key assumptions could materially affect the Company’s impairment analyses and the timing and amount of any impairment recognized. See Note 5 – Goodwill and Intangible Assets for further discussion on impairments of long-lived assets.

Intangible Assets

The Company’s indefinite-lived intangible asset (trade name) is evaluated for impairment at least annually and more frequently if events or changes in circumstances indicate that it is more likely than not that the asset’s fair value is less than its carrying amount. If the asset is impaired, the Company recognizes an impairment loss for the amount by which the carrying amount exceeds fair value. Finite-lived intangible assets are amortized over their estimated useful lives and are evaluated for impairment whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable.

See Note 5 – Goodwill and Intangible Assets for further discussion of the Company’s intangible assets.

Property and Equipment, net

Property and equipment, with the exception of the Company’s fleet vehicle finance leases, are recorded at cost and depreciated on a straight-line basis over their estimated useful lives. For buildings and leasehold improvements, the Company’s useful lives range from five years to 40 years; for machinery and equipment, useful lives range from three years to 10 years. Expenditures for maintenance and repairs are expensed as incurred. Leasehold improvements for the Company’s real estate operating leases are amortized over the lesser of the term of the related lease or the estimated useful lives of the improvements.

The following table summarizes the Company’s property and equipment:

(1)See additional information provided in Note 14 – Leases.

Depreciation and amortization expense on property and equipment was $9.8 million, $7.2 million and $6.4 million for the years ended December 31, 2025, 2024 and 2023, respectively.

Leases

A lease is a contract, or part of a contract, that conveys the right to control the use an identified asset for a period of time in exchange for consideration. At contract inception, the Company determines whether an arrangement contains a lease by assessing whether (i) the contract involves an identified asset and (ii) the Company has the right to control the use of that identified asset over the contract term. The Company determines lease classification as operating or finance at lease commencement.

With the exception of short-term leases (leases with an initial term of 12 months or less), the Company recognizes a right-of-use (“ROU”) asset and a lease liability at lease commencement. The lease liability is measured at the present value of the lease payments over the lease term and is discounted using the rate implicit in the lease when readily determinable; otherwise, the Company uses its incremental borrowing rate. The Company generally uses its incremental borrowing rate for real estate operating leases because the rate implicit in the lease is not readily determinable. For certain fleet vehicle leases classified as finance leases, the Company uses the stated rate in the lease when readily determinable.

The ROU asset is initially measured as the lease liability, adjusted for:

•lease payments made at or before commencement, less any lease incentives received;

•initial direct costs incurred; and

•(if applicable) accrued lease payments or deferred rent balances assumed or recognized.

Many of the Company’s operating lease contracts include options to extend or renew. The Company assesses the option for individual leases, and it generally considers the base term to be the term of lease contracts. See Note 14 – Leases for additional information.

The Company evaluates its ROU assets for impairment in accordance with the guidance for long-lived assets when events or changes in circumstances indicate that the carrying amount of the related asset group may not be recoverable. Recoverability is assessed using estimates of future undiscounted cash flows and other relevant economic and business factors.

Deferred Financing Costs

Deferred financing costs are deferred and amortized to interest expense using the effective interest rate method over the term of the related long-term debt agreement, and the straight-line method for the revolving credit agreement.

Debt issuance costs related to the issuance and/or extension, as applicable, of the Company’s term loans are reflected as a direct reduction from the carrying amount of long-term debt. Debt issuance costs related to revolving credit facilities are capitalized and reflected as an other asset.

Stock-Based Compensation

Stock-based compensation awards granted to executives, employees, former executives and non-employee directors are measured at grant date fair value and recognized as an expense over the requisite service period. For awards with service conditions only, the Company recognizes compensation expense on a graded vesting basis over the requisite service period for each separately vesting tranche based on the grant date fair value of the award. For awards with service and performance conditions, the Company recognizes compensation expense using the straight-line method over the requisite service period based on the grant date fair value of the award, and adjusts the amount of expense recognized for such awards based on management’s estimate of the probable outcome of the performance conditions. The cumulative effect of changes in the estimated probability of achieving the performance conditions is recorded in the period in which the change occurs.

The Company also grants awards that include market conditions. The grant date fair value of awards with market conditions is estimated using an appropriate valuation technique that incorporates the market condition. Because the market condition is reflected in the grant-date fair value, compensation expense for these awards is recognized over the requisite service period regardless of whether the market condition is ultimately achieved, provided the requisite service is rendered. The Company has elected to account for forfeitures as they occur to determine the amount of compensation expense to be recognized each period. See also Note 17 – Management Incentive Plans in the accompanying notes to the Company’s consolidated financial statements for further information.

Income Taxes

The provision for income taxes includes federal, state and local income taxes. The Company accounts for income taxes in accordance with ASC Topic 740, Income Taxes, which requires the use of the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply in the periods in which the temporary differences are expected to reverse. The effect of changes in tax laws and tax rates on deferred tax assets and liabilities is recognized in the provision for income taxes in the period that includes the enactment date.

The Company evaluates the realizability of deferred tax assets and establishes a valuation allowance when, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. In assessing realizability, the Company considers, among other factors, historical and projected future taxable income, the reversal of existing taxable temporary differences, and available tax planning strategies.

The Company recognizes the effect of uncertain tax positions only if it is more likely than not that the position will be sustained upon examination, based on the technical merits of the position. The amount recognized is measured as the largest amount of tax benefit that is greater than 50 percent likely to be realized upon ultimate settlement with the taxing authority. Interest and penalties related to unrecognized tax benefits are recognized in income tax expense.

Fair Value Measurements

The Company measures certain assets and liabilities at fair value in accordance with ASC Topic 820, Fair Value Measurements and Disclosures, which defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. ASC Topic 820 establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to measurements involving significant unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are as follows:

•Level 1 — inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that are accessible at the measurement date;

•Level 2 — inputs other than quoted prices included in Level 1 that are observable for the asset or liability either directly or indirectly such as quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of assets or liabilities; and

•Level 3 — unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.

See also Note 9 – Fair Value Measurements in the accompanying notes to the Company’s consolidated financial statements for further information.

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. ASU 2025-05 is effective for annual and interim periods beginning after December 15, 2025, and interim reporting periods in those years. Entities that elect the practical expedient and, if applicable, make the accounting policy election are required to apply the amendments prospectively. The Company is currently evaluating the potential impact of adopting ASU 2025-05 on its consolidated financial statements and 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 consolidated financial statements and disclosures.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures (Topic 740). This update requires entities to disclose additional information with respect to the effective tax rate reconciliation and to disclose the disaggregation by jurisdiction of income tax expense and income taxes paid. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. The Company adopted ASU 2023-09 in its 2025 Annual Report on Form 10-K and elected to apply the guidance on a retrospective basis. This standard did not have a material impact on the Company's consolidated financial position, results of operations or cash flows, but affected certain of its financial statement disclosures as discussed above.

Note 3 –Acquisitions

Pioneer Power Transaction

On July 1, 2025 (the “Pioneer Power Effective Date”), LFS and the former owners of Pioneer Power (the “Pioneer Power Seller”) entered into a Purchase Agreement (the “Pioneer Power Purchase Agreement”) pursuant to which LFS purchased all of the outstanding equity interests in Pioneer Power from the Pioneer Power Seller (the “Pioneer Power Transaction”). Prior to the acquisition, Pioneer Power was 100% owned through an employee stock ownership plan. The Pioneer Power Transaction closed on the Pioneer Power Effective Date. As a result of the Pioneer Power Transaction, Pioneer Power became a wholly-owned indirect subsidiary of the Company. Pioneer Power is a provider of industrial and institutional mechanical solutions serving healthcare, food, power/utility, oil refining and other select markets in the greater Twin Cities region of Minnesota and upper Midwest region. The acquisition further expands the Company’s footprint in the core Midwest and extends its reach into new geographic markets in the upper Midwest regions.

Total purchase price paid by the Company for the Pioneer Power Transaction at closing was $66.1 million (the “Pioneer Power Closing Purchase Price”), which was funded through a combination of available cash on hand and borrowings under the Company's revolving credit facility. The payment is subject to typical adjustments for working capital. Of the consideration paid to the Pioneer Power Seller, approximately $4.1 million was held in escrow for indemnification purposes. The purchase price was subject to customary post-closing adjustments.

Allocation of Purchase Price. The Pioneer Power Transaction was accounted for as a business combination using the acquisition method. As a result of the acquisition, the Company recognized $37.5 million of goodwill, which was allocated between the Company's ODR and GCR segments and is fully deductible for tax purposes. Such goodwill primarily related to anticipated future earnings. The fair value estimates for the assets acquired and liabilities assumed, as well as the Company's estimates and assumptions, are subject to change as the Company obtains additional information during the measurement period. Measurement period adjustments are reflected as if the adjustments had been made as of the Pioneer Power Effective Date. The impact of all changes that do not qualify as measurement period adjustments have been included in current period earnings.

The following table summarizes the purchase price and estimated fair values of assets acquired and liabilities assumed as of the Pioneer Power Effective Date, with any excess of purchase price over estimated fair value of the identified net assets acquired recorded as goodwill.

(1)Measurement period adjustments recorded during the quarter ended December 31, 2025 reflect changes to the fair value of contract assets acquired and contract liabilities assumed, resulting in a net increase of approximately $0.9 million to goodwill.

As of December 31, 2025, the allocation of the purchase price has not been finalized with respect to the valuation of identifiable intangible assets acquired, the fair value of certain tangible assets acquired and liabilities assumed, goodwill and tax related matters. A final determination of the fair value of assets acquired and liabilities assumed relating to the acquisition could differ from the preliminary purchase price allocation. The Company expects to finalize the valuation and complete the purchase price allocation as soon as practicable, but no later than one year from the Pioneer Power Effective Date.

For working capital items, such as cash and cash equivalents, accounts receivable, other current assets, accounts payable and accrued expenses and other current liabilities, the carrying value was assumed to represent the fair value of these assets and liabilities due to their current nature. There was no difference between the contract value and fair value of accounts receivable acquired.

In connection with the acquisition of Pioneer Power, the Company acquired property and equipment with an aggregate fair value of approximately $6.3 million. The property and equipment primarily consisted of land, buildings and improvements and related property of the former owners, as well as certain machinery and equipment utilized in its operations. The fair values of the acquired assets were determined based on independent appraisals and management estimates using the cost approach. Significant unobservable inputs in the estimate of fair value under this approach included management's assumptions about the replacement costs for similar assets, the relative age of the acquired assets and any potential economic or functional obsolescence associated with the acquired assets. As a result, the estimated fair value of the property and equipment represented a Level 3 fair value measurement.

As part of the preliminary purchase price allocation, the Company identified certain definite-lived intangible assets associated with customer relationships with third-party customers, acquired backlog and the acquired trade name and trademarks. The fair value of the customer relationships with third-party customers and acquired backlog was determined using the multi-period excess earning method under the income approach. The multi-period excess earnings method is a variation of the discounted cash-flow analysis, which isolates the cash flows that can be associated with a single intangible asset and measures fair value by discounting it back to present value. The fair value of the acquired trade name and trademarks intangible asset was determined using an income approach, specifically known as the relief-from-royalty method. This method requires identifying the future revenue that would be generated by the trademark, multiplying it by a royalty rate deemed to be avoided through ownership of the asset and discounting the projected royalty savings amounts back to the acquisition date. The royalty rate used in the valuation was based on a consideration of market rates for similar categories of assets. Some of the more significant estimates and assumptions inherent in determining the fair value of the identifiable intangible assets are associated with forecasting cash flows and profitability, which represent Level 3 inputs.

The Company calculates amortization of the acquired intangible assets using the straight-line method over the estimated useful lives of each acquired intangible asset. The estimated annual amortization expense is approximately $2.3 million for 2026, $1.6 million for 2027 and $1.5 million for each of the following three years.

Intangible assets, net as of December 31, 2025 are detailed below.

In connection with the Pioneer Power Transaction, the Company entered into certain retention-related bonus arrangements with key employees of Pioneer Power. These arrangements are designed to promote continued employment and support integration efforts following the acquisition. Retention-related compensation is recognized as expense ratably over the service period, which runs through December 2027, and is contingent on continued employment. The retention-related bonus arrangements are separate from, and not part of, the consideration transferred in the acquisition. Accordingly, these amounts were not included in the determination of purchase price or the allocation of purchase consideration under ASC 805, Business Combinations. Related expenses are recognized within acquisition-related retention expense and contingent consideration in the consolidated statements of operations. During the year ended December 31, 2025, the Company recognized $0.2 million in retention-related expenses associated with the Pioneer Power Transaction.

Consolidated Mechanical Transaction

On December 2, 2024 (the “Consolidated Mechanical Effective Date”), LFS, Consolidated Mechanical, and the owner of Consolidated Mechanical (the “Consolidated Mechanical Seller”) entered into a Purchase Agreement (the “Consolidated Mechanical Purchase Agreement”) pursuant to which LFS purchased all of the outstanding equity interests in Consolidated Mechanical from the Consolidated Mechanical Seller (the “Consolidated Mechanical Transaction”). The Consolidated Mechanical Transaction closed on the Consolidated Mechanical Effective Date. As a result of the Consolidated Mechanical Transaction, Consolidated Mechanical became a wholly-owned indirect subsidiary of the Company. Consolidated Mechanical serves the heavy industrial, power and commercial markets. Consolidated Mechanical is a premier provider of mechanical, millwright, steel fabrication, plumbing construction, maintenance, and outage services to owners of complex process systems in the industrial sector. The acquisition extends the Company’s reach into the industrial sector, with new exposure to the power generation, food processing, manufacturing, and metal markets in Kentucky, Illinois and Michigan.

Total purchase price paid by the Company for the Consolidated Mechanical Transaction at closing was $23.0 million (the “Consolidated Mechanical Closing Purchase Price”), which was funded by cash on hand. The payment is subject to typical adjustments for working capital. Of the consideration paid to the Consolidated Mechanical Seller, approximately $0.3 million was held in escrow for indemnification purposes. The purchase price was subject to customary post-closing adjustments. In addition, the Consolidated Mechanical Seller may receive up to an aggregate of $2.0 million in cash, consisting oftwo individual tranches of $1.0 million pursuant to the terms of the Consolidated Mechanical Purchase Agreement, if the gross profit of Consolidated Mechanical equals or exceeds approximately (i) $6.8 million in the 12-month period beginning on the Consolidated Mechanical Effective Date (the “First Consolidated Mechanical Earnout Period”) or (ii) $6.8 million in the 12-month period beginning on the first anniversary of the Consolidated Mechanical Effective Date (the “Second Consolidated Mechanical Earnout Period” and together with the First Consolidated Mechanical Earnout Period, the “Consolidated Mechanical Earnout Payments”).

Allocation of Purchase Price. The Consolidated Mechanical Transaction was accounted for as a business combination using the acquisition method. As a result of the acquisition, the Company recognized $11.1 million of goodwill, which was fully allocated to the Company's ODR segment and fully deductible for tax purposes. Such goodwill primarily related to anticipated future earnings. The fair value estimates for the assets acquired and liabilities assumed, as well as the Company's estimates and assumptions, were subject to change as the Company obtains additional information during the measurement period. During the measurement period, if the Company obtained new information regarding facts and circumstances that existed as of the Consolidated Mechanical Effective Date that, if known, would have resulted in revised estimated values of those assets or liabilities, the Company would have accordingly revised its fair value estimates and purchase price allocation. Measurement period adjustments are reflected as if the adjustments had been made as of the Consolidated Mechanical Effective Date. Any changes that do not qualify as measurement period adjustments are recognized in earnings in the period in which the adjustment is identified. The Company finalized its purchase price allocation during the third quarter of 2025.

The following table summarizes the purchase price and estimated fair values of assets acquired and liabilities assumed as of the Consolidated Mechanical Effective Date, with any excess of purchase price over estimated fair value of the identified net assets acquired recorded as goodwill.

(1)Measurement period adjustments recorded during the first half of 2025 included changes in the total cash consideration for the Consolidated Mechanical Transaction, resulting in a net increase less than $0.1 million to goodwill. The measurement period adjustments related to certain working capital adjustments made in connection with the finalization of the transaction’s closing date cash consideration.

Kent Island Transaction

On September 3, 2024 (the “Kent Island Effective Date”), LFS, Kent Island, and the owner of Kent Island (the “Kent Island Seller”) entered into a Purchase Agreement (the “Kent Island Purchase Agreement”) pursuant to which LFS purchased all of the outstanding equity interests in Kent Island from the Kent Island Seller (the “Kent Island Transaction”). The Kent Island Transaction closed on the Kent Island Effective Date. As a result of the Kent Island Transaction, Kent Island became a wholly-owned indirect subsidiary of the Company. Kent Island is a leading provider of building systems solutions in the greater Washington, DC metro area, including suburban Maryland and Northern Virginia. Kent Island excels in designing, engineering, installing, servicing, and maintaining mechanical and plumbing systems for complex facilities. The acquisition expands the Company’s market share within its existing operating footprint, provides further exposure to an attractive customer base and supports the Company's continued ODR growth strategy.

Total purchase price paid by the Company for the Kent Island Transaction at closing was $15.0 million (the “Kent Island Closing Purchase Price”), which was funded by cash on hand. The payment was subject to typical adjustments for working capital. Of the consideration paid to the Kent Island Seller, approximately $0.4 million was held in escrow for indemnification purposes. The purchase price was subject to customary post-closing adjustments. In addition, the Kent Island Seller may receive up to an aggregate of $5.0 million in cash, consisting oftwo individual tranches of $2.5 million pursuant to the terms of the Kent Island Purchase Agreement, if the gross profit of Kent Island equals or exceeds approximately (i) $3.3 million in the 12-month period beginning on the Kent Island Effective Date (the “First Kent Island Earnout Period”) or (ii) $0.2 million in the 12-month period beginning on the first anniversary of the Kent Island Effective Date (the “Second Kent Island Earnout Period” and together with the First Kent Island Earnout Period, the “Kent Island Earnout Payments”).

Allocation of Purchase Price. The Kent Island Transaction was accounted for as a business combination using the acquisition method. As a result of the acquisition, the Company recognized $5.6 million of goodwill, which was allocated between the Company's ODR and GCR segments and fully deductible for tax purposes. Such goodwill primarily related to anticipated future earnings. The fair value estimates for the assets acquired and liabilities assumed, as well as the Company's estimates and assumptions, were subject to change as the Company obtained additional information during the measurement period. During the measurement period, if the Company obtained new information regarding facts and circumstances that existed as of the Kent Island Effective Date that, if known, would have resulted in revised estimated values of those assets or liabilities, the Company would have accordingly revised its fair value estimates and purchase price allocation. Measurement period adjustments are reflected as if the adjustments had been made as of the Kent Island Effective Date. Any changes that do not qualify as measurement period adjustments are recognized in earnings in the period in which the adjustment is identified. The Company finalized its purchase price allocation during the third quarter of 2025.

The following table summarizes the purchase price and estimated fair values of assets acquired and liabilities assumed as of the Kent Island Effective Date, with any excess of purchase price over estimated fair value of the identified net assets acquired recorded as goodwill.

(1)Measurement period adjustments recorded during the year-ended December 31, 2024 included changes in the total cash consideration for the Kent Island Transaction, resulting in a net increase of approximately $0.7 million to goodwill. The measurement period adjustments related to certain working capital adjustments made in connection with the finalization of the transactions closing date cash consideration.

(2)Measurement period adjustments recorded during the first quarter of 2025 reflect changes to the fair value of contract assets acquired, resulting in a net increase of approximately $0.1 million to goodwill.

Impact of Acquisitions on the Company’s Financial Statements

The acquisitions of Pioneer Power, Consolidated Mechanical, and Kent Island contributed in the aggregate approximately $109.1 million of total incremental revenue for the year ended December 31, 2025. Acquisition-related revenue represents incremental revenue generated in 2025 by Pioneer Power, Consolidated Mechanical and Kent Island only for the twelve-month period subsequent to their respective acquisition dates. After such period, the results of acquired businesses are included within the Company’s organic operations, and period-over-period changes are discussed on a combined basis. The acquired companies’ incremental impact on net income for the year ended December 31, 2025 was not material.

Note 4 –Revenue from Contracts with Customers

The Company’s revenue is primarily derived from construction-type and services contracts to deliver MEPC systems services to its customers. Such work is primarily performed under fixed-price, modified fixed-price, and time and materials contracts over periods of typically less than two years.

Construction-type contract revenue is primarily derived from fixed-price and modified fixed-price contracts. For the majority of these contracts, the Company’s performance obligations are satisfied over time because the customer controls the asset as it is created or enhanced or because the Company’s performance does not create an asset with an alternative use and the Company has an enforceable right to payment for performance completed to date. For contracts satisfied over time, the Company recognizes revenue using an input method based on costs incurred relative to total estimated costs at completion (the cost-to-cost method), which management believes depicts the transfer of control of services to the customer. The Company believes its extensive experience with MEPC systems projects, together with its internal cost estimation and review processes, enables it to reasonably estimate contract costs and mitigate the risk of cost overruns.

With respect to service contracts, the Company’s service arrangements generally include (i) fixed-price service contracts, typically for maintenance, repair and retrofit work over a period, commonly one year, and (ii) time and materials or similar service work performed on an as-needed basis. Revenue from fixed-price service contracts is generally recognized over time on a systematic basis that depicts performance over the contract term, which is typically on a straight-line basis when services are provided evenly over the contract period. Revenue derived from time and materials and other service work is recognized when the services are performed.

The Company generally invoices customers on a monthly basis based on a schedule of values that breaks down the contract amount into discrete billing items. Costs and estimated earnings in excess of billings on uncompleted contracts are recorded as a contract asset until billable under the contract terms. Billings in excess of costs and estimated earnings on uncompleted contracts are recorded as a contract liability until the related revenue is recognizable.

Contract Assets and Contract Liabilities

Contract assets represent the Company’s conditional right to consideration for goods or services transferred to customers when that right is conditioned on something other than the passage of time. Contract liabilities represent the Company’s obligation to transfer goods or services to customers for which consideration has been received or is due.

The Company’s contracts commonly include retainage provisions, pursuant to which a portion of billed consideration is contractually withheld by customers until achievement of specified contractual milestones, such as substantial completion, final acceptance, or satisfaction of defined performance criteria. Retainage does not represent an unconditional right to payment and is therefore not considered a trade receivable. Accordingly, retainage is reflected within contract balances based on the related net billing position.

Contract assets include costs and estimated earnings in excess of billings on uncompleted contracts and retainage associated with contracts for which the Company has a conditional right to consideration. The components of the contract asset balances as of the respective dates were as follows:

Contract liabilities

Contract liabilities include billings in excess of contract costs and estimated earnings on uncompleted contracts, provisions for losses and amounts related to retainage associated with overbilled contracts, which reduce billings in excess of costs until such payment become payable under contract terms. The components of the contract liability balances as of the respective dates were as follows:

Billings in excess of costs and estimated earnings on uncompleted contracts represent the excess of contract billings to date over the amount of contract costs and profits (or contract revenue) recognized to date. The balance may fluctuate depending on the timing of contract billings and the recognition of contract revenue.

Provisions for losses are recognized in the consolidated statements of operations at the uncompleted performance obligation level for the amount of total estimated losses in the period that evidence indicates that the estimated total cost of a performance obligation exceeds its estimated total revenue.

Claims and Unapproved Change Orders

Contract assets may include amounts related to claims and unapproved change orders, which arise when there is a dispute regarding changes in scope or pricing or when additional work is performed prior to execution of a contractual amendment. The Company estimates recoveries related to claims and unapproved change orders as variable consideration using the most likely amount method, to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur. Such amounts are billable upon resolution and execution of contractual amendments. The estimated net realizable value of claims and unapproved change orders included within contract assets and contract liabilities was $13.6 million and $10.9 million as of December 31, 2025 and 2024, respectively.

Net Contract Position

The net underbilling (overbilling) position for contracts in process consisted of the following:

Revisions in Contract Estimates

The Company recorded revisions in its contract estimates for certain ODR and GCR projects. During the year ended December 31, 2025, the Company recorded material gross profit write-downs ontwo ODR segment projects for a total of $1.1 million that had a net gross profit impact of $0.5 million or more. During the year ended December 31, 2025, the Company recorded material gross profit write-ups ontwo GCR projects for a total of $2.2 million.

During the year ended December 31, 2024, the Company recorded a material gross profit write-ups onfour ODR segment projects for a total of $3.9 million that had a net gross profit impact of $0.5 million or more. During the year ended December 31, 2024, the Company recorded material gross profit write-ups of $3.3 million onthree GCR projects and material gross profit write-downs ontwo GCR projects for a total of $1.4 million.

Remaining Performance Obligations

Remaining performance obligations represent the transaction price of firm orders for which work has not been performed and exclude unexercised contract options. The Company’s remaining performance obligations include projects that have a written award, a letter of intent, a notice to proceed or an agreed upon work order to perform work on mutually accepted terms and conditions.

As of December 31, 2025, the aggregate amount of the transaction prices allocated to the remaining performance obligations of the Company's ODR and GCR segment contracts were $234.3 million and $141.8 million, respectively. The Company currently estimates that 82% and 77% of its ODR and GCR segment remaining performance obligations as of December 31, 2025, respectively, will be recognized as revenue during 2026, with the substantial majority of remaining performance obligations to be recognized within 24 months, although the timing of the Company’s performance is not always under its control.

Additionally, the difference between remaining performance obligations and backlog is due to the exclusion of a portion of the Company’s ODR agreements under certain contract types from the Company’s remaining performance obligations as these contracts can be canceled for convenience at any time by the Company or the customer without considerable cost incurred by the customer.

Note 5 –Goodwill and Intangible Assets

Goodwill

Goodwill was $70.6 million and $33.0 million as of December 31, 2025 and 2024, respectively. The Company tests its goodwill and indefinite-lived intangible assets allocated to its reporting units for impairment annually on October 1, or more frequently if events or circumstances indicate that it is more likely than not that the fair value of its reporting units and indefinite-lived intangible assets are less than their carrying amount. The Company has the option to assess goodwill for possible impairment by performing a qualitative analysis to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. A quantitative assessment is performed if the qualitative assessments results in a more likely than not determination or if a qualitative assessment is not performed.

On October 1, 2025, the Company performed a qualitative assessment. In conducting that qualitative assessment, the Company analyzed a variety of events or factors that may influence the fair value of the reporting unit or indefinite-life intangible, including, but not limited to: if applicable; changes in the carrying amount of the reporting unit or indefinite-life intangible; actual and projected revenue and operating margin; relevant market data for both the Company and its peer companies; industry outlooks; macroeconomic conditions; liquidity; changes in key personnel; and the Company's competitive position. Significant judgment was used to evaluate the totality of these events and factors to make the determination of whether it is more likely than not that the fair value of the reporting units or indefinite-life intangible is less than its carrying value. No impairment losses were identified as a result of its qualitative assessment during the year ended December 31, 2025.

The following table summarizes the carrying amount and changes in goodwill associated with the Company's segments for the years ended December 31, 2025 and 2024.

(1) Includes certain adjustments to preliminary estimates of fair value within the measurement period of up to one-year from the date of the Industrial Air transaction. Measurement period adjustments related to certain working capital adjustments.

(2) In connection with the Kent Island Transaction, the Company recorded preliminary goodwill of $4.8 million. During the fourth quarter of 2024, the Company recognized certain adjustments to preliminary estimates of fair value within the measurement period of up to one-year from the date of the Kent Island Transaction. The measurement period adjustments amounted to $0.7 million and related to certain working capital adjustments made in connection with the finalization of the transaction’s closing date cash consideration. In addition, during the first quarter of 2025, the Company recognized further adjustments to the preliminary estimates of fair value within the measurement period of $0.1 million related to the receipt of additional information regarding the facts and circumstances that existed as of the acquisition date.

(3)During the first half of 2025, the Company recognized certain adjustments to the preliminary estimates of fair value within the measurement period amounting to less than $0.1 million associated with certain working capital adjustments made in connection with the finalization of the transaction’s closing date cash consideration.

(4)Measurement period adjustments recorded during the quarter ended December 31, 2025 reflect changes to the fair value of contract assets acquired and contract liabilities assumed, resulting in a net increase of approximately $0.9 million to goodwill.

Intangible Assets

The Company reviews intangible assets with definite lives subject to amortization whenever events or changes in circumstances (triggering events) indicate that the carrying amount of an asset may not be recoverable. Intangible assets with definite lives subject to amortization are amortized on a straight-line or accelerated basis with estimated useful lives ranging from 1 to 15 years. Events or circumstances that might require impairment testing include the identification of other impaired assets within a reporting unit, loss of key personnel, the disposition of a significant portion of a reporting unit, a significant decline in stock price, or a significant adverse change in the Company’s business climate or regulations affecting the Company.

The Company didnot recognize an impairment charge on its indefinite-lived intangible assets for the years ended December 31, 2025, 2024 and 2023.

Definite-lived and indefinite-lived intangible assets consist of the following:

(1) The Company has determined that its trade name has an indefinite useful life. The Limbach trade name has been in existence since the Company’s founding in 1901 and therefore is an established brand within the industry.

Total amortization expense for the Company’s definite-lived intangible assets was $8.4 million, $4.7 million and $1.9 million for the years ended December 31, 2025, 2024 and 2023, respectively. For the years ended December 31, 2025, 2024 and 2023, amortization expense included approximately $0.1 million, $0.1 million and less than $0.1 million of amortization expense related to a below-market lease recognized as a result of the Industrial Air transaction, which was recorded as an increase to the Company’s operating lease right-of-use assets on its consolidated balance sheet. Amortization expense associated with the Company’s below-market lease arrangement is expected to be approximately $0.1 million for each of the next five years and is not included in the estimated amortization expense table below.

The estimated remaining useful lives of definite-lived intangible assets are as follows:

Estimated amortization expense is as follows for the years ending December 31:

Note 6 –Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities are comprised of the following:

The Company’s construction-type contracts regularly include warranties to end customers that guarantee the work performed against defects in workmanship and the material it supplies. These standard warranties are assurance-type warranties and do not offer any additional services. Therefore, these assurance-type warranties are not considered separate performance obligations and the expected cost of assurance-type warranties are accrued as an expense within cost of revenue. The accounting for assurance-type warranties under ASC Topic 606 did not have a material impact to the consolidated financial statements as of December 31, 2025, 2024 and 2023.

The Company also offers service-type warranties on certain construction-type projects. The accounting for service-type warranties under ASC Topic 606 did not have a material impact to the consolidated financial statements as of December 31, 2025, 2024 and 2023.

Note 7 –Debt

Long-term debt consists of the following obligations as of:

Maturities of long-term debt and finance leases at December 31, 2025 are as follows:

Wintrust Revolving Loans

The Company maintains a senior secured revolving credit facility with Wheaton Bank & Trust Company, N.A., a subsidiary of Wintrust Financial Corporation (collectively, “Wintrust”), as administrative agent, pursuant to a Second Amended and Restated Credit Agreement originally entered into on May 5, 2023.

On June 27, 2025, LFS, LHLLC, and other designated parties entered into a second amendment to the second amended and restated Wintrust Credit Agreement (the “Second Amendment to the Second A&R Wintrust Credit Agreement”) with Wintrust, as administrative agent, and the other lenders party thereto. The Second Amendment to the Second A&R Wintrust Credit Agreement provides for, among other things, (i) an upsize of the aggregate principal amount of the senior secured revolving credit facility from $50.0 million to $100.0 million, (ii) modifying the definition of “L/C Sublimit” to increase the sublimit for the issuance of letters of credit from $10.0 million to $20.0 million, (iii) an extension of the revolving credit scheduled maturity date from February 24, 2028 to July 1, 2030, (iv) a decrease in the applicable margins for Term SOFR and Prime Rate (each defined in the Second Amendment to the Second A&R Wintrust Credit Agreement) revolving loans as determined with reference to LFS’s Senior Leverage Ratio (as defined in the Second Amendment to the Second A&R Wintrust Credit Agreement), (v) a term loan conversion feature, allowing LFS, subject to certain conditions, to convert outstanding revolving loans into one or more term loan tranches, (vi) the removal of certain covenant requirements, specifically in relation to LFS’s Borrowing Base, as formerly defined in the Second A&R Wintrust Credit Agreement, and (vii) modification to certain defined terms to reflect updated operational and financial terms.

Following the execution of the Second Amendment to the Second A&R Wintrust Revolving Loan, the Second A&R Wintrust Revolving Loan bears interest, at LFS’s option, at either the Term SOFR (with a 0.15% floor) plus 2.50% or the Prime Rate (with a 3.0% floor), subject to a 95 basis point step-down based on the ratio between the senior debt of the Company and its subsidiaries to the EBITDA of LFS and its subsidiaries for the most recently ended four fiscal quarters.

As of both December 31, 2025 and 2024, the Company had $10.0 million in borrowings outstanding under the Wintrust Revolving Loans. During the years ended December 31, 2025 and 2024, the maximum outstanding borrowings under the Wintrust Revolving Loan at any time was $50.0 million and $10.0 million, respectively, and the average daily balance was $22.3 million and $10.0 million, respectively. For the years ended December 31, 2025 and 2024, the Company incurred interest on the Wintrust Revolving Loans at a weighted average annual interest rate of 6.04% and 5.72%, inclusive of the net impact associated with the Company's interest rate swap arrangement.

At December 31, 2025, the Company had irrevocable letters of credit in the amount of $5.1 million with its lender to secure obligations under its self-insurance program and

As of December 31, 2025, the Company was in compliance with all financial maintenance covenants as required by the Second A&R Credit Agreement.

The following is a summary of the applicable margin and commitment fees payable on the Wintrust Revolving Loan, as amended, credit commitment:

Interest Rate Swap

The Company is party to an interest rate swap agreement to manage the risk associated with a portion of its variable-rate long-term debt. The interest rate swap involves the exchange of fixed rate and variable-rate payments without the exchange of the underlying notional amount on which the interest payments are calculated. The swap agreement became effective on July 14, 2022 and will terminate on July 31, 2027. The notional amount of the swap agreement is $10.0 million with a fixed interest rate of 3.12% plus the SOFR Applicable Margin. If the one-month SOFR (as defined in the Second Amendment to the Second A&R Credit Agreement) is above the fixed rate, the counterparty pays the Company, and if the one-month SOFR is less than the fixed rate, the Company pays the counterparty, the difference between the fixed rate of 3.12% and the one-month SOFR. The Company has not designated this instrument as a hedge for accounting purposes. As a result, the change in fair value of the derivative instrument is recognized directly in earnings on the Company's consolidated statements of operations as a gain or loss on interest rate swap.

Sale-Leaseback Financing Transaction

On September 29, 2022, the Company completed a sale and leaseback transaction related to its facility in Pontiac, Michigan (the “Pontiac Facility”), with an aggregate transaction value of approximately $7.8 million, consisting of a purchase price of approximately $5.4 million and up to $2.4 million of tenant improvement allowances.

In connection with the transaction, the Company entered into a 25-year lease agreement withtwo five-year renewal options. Annual minimum rent is approximately $0.5 million, payable monthly and subject to annual escalations of approximately 2.5%. The lease includes a one-time termination option at the end of the fifteenth lease year, which would require payment of a termination fee of approximately $1.7 million if exercised.

The Company accounted for the transaction as a failed sale-leaseback and financing arrangement under ASC 842, as the lease was classified as a finance lease and control of the property did not transfer. Accordingly, no gain or loss was recognized, and the property was not derecognized from the Company’s consolidated balance sheets. Proceeds received were recorded as a financing liability and are repaid through lease payments, which are allocated between principal and interest.

As of December 31, 2025, the financing liability was $5.0 million, net of issuance costs, which was recognized within long-term debt on the Company's consolidated balance sheets. Interest expense associated with the financing was approximately $0.5 million for each of the years ended December 31, 2025, 2024 and 2023.

Note 8 –Equity

The Company’s second amended and restated certificate of incorporation currently authorizes the issuance of 100,000,000 shares of common stock, par value $0.0001, and 1,000,000 shares of preferred stock, par value $0.0001.

Warrants

In conjunction with the Company's initial public offering, the Company issued Public Warrants, Private Warrants and $15 Exercise Price Sponsor Warrants. The Company issued certain Merger Warrants and Additional Merger Warrants in conjunction with the Company's business combination with LHLLC in July 2016. On July 20, 2021, the Public Warrants, Private Warrants, and Additional Merger Warrants expired by their terms. During 2023,600,000 warrants exercisable forone share of common stock at an exercise price of $15.00 per share (“$15 Exercise Price Sponsor Warrants”) and 606,476 warrants exercisable forone share of common stock at an exercise price of $12.50 per share (“Merger Warrants”) were exercised on a cashless basis by the holders of the warrants, which resulted in the warrants being converted into 167,564 and 274,742 shares of the Company's common stock, respectively. The remaining 23,167 unexercised Merger Warrants expired by their terms on July 20, 2023.

Incentive Plan

Upon the consummation of the Company’s business combination with LHLLC in July 2016, the Company adopted an omnibus incentive plan (the “Omnibus Incentive Plan”) pursuant to which equity awards may be granted thereunder.

In March 2023, the Board of Directors approved certain amendments to the Company's Omnibus Incentive Plan (the “2023 Amended and Restated Omnibus Incentive Plan”) to increase the number of shares of the Company's common stock that may be issued pursuant to awards by 450,000, for a total of 3,050,000 shares, and extended the term of the plan so that it will expire on the tenth anniversary of the date the stockholders approve the 2023 Amended and Restated Omnibus Incentive Plan. The amendments were acted upon by the Company's stockholders at the Annual Meeting held on June 22, 2023.

In April 2025, the Board of Directors approved certain amendments to the 2023 Amended and Restated Omnibus Incentive Plan to make certain changes related to the treatment of death, disability, retirement and reduction in force as it relates to the plan participants. The amendments were acted upon by the Company's stockholders at the Annual Meeting held on June 11, 2025. See Note 17 – Management Incentive Plans for a discussion of the Company's management incentive plans for restricted stock units (“RSUs”) granted, vested, forfeited and remaining unvested.

Share Repurchase Program

In December 2025, the Company announced that its Board of Directors authorized a share repurchase program (the “Share Repurchase Program”), pursuant to which the Company may, from time to time, purchase up to $50.0 million of shares of its common stock through December 15, 2027. Share repurchases may be executed through various means, including, without limitation, open market transactions, privately negotiated transactions or by other means in accordance with federal securities laws. Repurchases may also be made under Rule 10b5-1 plans. The Share Repurchase Program does not obligate the Company to acquire any particular amount of common stock, and the program may be suspended or terminated by the Company at any time at its discretion without prior notice. As of December 31, 2025, the Company has not repurchased any common stock under its Share Repurchase Program.

Employee Stock Purchase Plan

Upon approval of the Company's stockholders on May 30, 2019, the Company adopted the Limbach Holdings, Inc. 2019 Employee Stock Purchase Plan (the “ESPP”). On January 1, 2020, the ESPP went into effect. The ESPP enables eligible employees, as defined by the ESPP, the right to purchase the Company’s common stock through payroll deductions during consecutive subscription periods at a purchase price of 85% of the fair market value of a share of the Company’s common stock at the end of each offering period. Annual purchases by participants are limited to the number of whole shares that can be purchased by an amount equal toten percent of the participant's compensation or $5,000, whichever is less. Each offering period of the ESPP lastssix months, commencing on January 1st and July 1st of each year. The amounts collected from participants during a subscription period are used on the exercise date to purchase full shares of common stock. Participants may withdraw from an offering before the exercise date and obtain a refund of amounts withheld through payroll deductions. Compensation cost, representing the 15% discount applied to the fair market value of common stock, is recognized on a straight-line basis over thesix-month vesting period during which employees perform related services. Under the ESPP,500,000 shares are authorized to be issued. For the years ended December 31, 2025 and 2024, the Company issued 4,496 and 6,090 shares of its common stock, respectively, to participants in the ESPP who contributed to the plan during these periods. As of December 31, 2025,378,370 shares remain available for future issuance under the ESPP.

Note 9 –Fair Value Measurements

The Company believes that the carrying amounts of its financial instruments, including cash and cash equivalents, trade accounts receivable and accounts payable, consist primarily of instruments without extended maturities, which approximate fair value primarily due to their short-term maturities and low risk of counterparty default. The Company considers all highly liquid investments purchased with a maturity of 90 days or less on the date of purchase to be cash equivalents. Cash equivalents as of December 31, 2025 and 2024 consisted of overnight repurchase agreements in which cash from the Company's main operating checking account is invested overnight in highly liquid, short-term investments and certain investments in money market funds sponsored by a large financial institution. For the years ended December 31, 2025, 2024 and 2023, the Company recognized interest income in the aggregate of approximately $0.8 million, $2.2 million and $1.2 million, respectively. The Company has not experienced any losses in its cash and cash equivalents and management believes the Company is not exposed to significant credit risk with respect to such accounts.

Wintrust Revolving Loans

The Company also believes that the carrying value of the Wintrust Revolving Loans approximates its respective fair value due to the variable rate on such debt. As of December 31, 2025, the Company determined that the fair value of the Wintrust Revolving Loans was $10.0 million. Such fair value was determined using discounted estimated future cash flows using level 3 inputs.

Earnout Payments

As a part of the total consideration for the Company's July 2023 acquisition of ACME, the former owner of ACME is eligible to receive up to an aggregate of $2.5 million in cash, consisting oftwo individual tranches of $0.5 million and $2.0 million pursuant to the terms of the purchase agreement, if the gross profit of ACME equals or exceeds (i) $2.0 million in the 12-month period beginning from the closing date of the transaction (the “First ACME Earnout Period”) or (ii) $2.5 million in the 12-month period beginning on the first anniversary of the closing date of the transaction (the “Second ACME Earnout Period” and together with the First ACME Earnout Period, the “ACME Earnout Payments”). The Company initially recognized $1.5 million in contingent consideration as of the closing date of the transaction. The fair value of contingent ACME Earnout Payments is based on generating growth rates on the projected gross margins of ACME and calculating the associated contingent payments based on achieving the earnout targets, which are reassessed each reporting period. In September 2024 and October 2025, the Company made payments of $0.5 million and $2.0 million, respectively, to the former owner of ACME related to the First and Second ACME Earnout Periods.

As a part of the total consideration for Company's November 2023 acquisition of Industrial Air, the former owner of Industrial Air is eligible to receive up to an aggregate of $6.5 million in cash, consisting oftwo individual tranches of $3.0 million and $3.5 million pursuant to the terms of the purchase agreement, if the gross profit of Industrial Air equals or exceeds (i) $7.6 million in the 12-month period beginning on the closing date of the transaction (the “First IA Earnout Period”) or (ii) $8.8 million in the 12-month period beginning on the first anniversary of the closing date of the transaction (the “Second IA Earnout Period” and together with the First IA Earnout Period, the “IA Earnout Payments”). The Company initially recognized $3.2 million in contingent consideration as of the closing date of the transaction. The fair value of contingent IA Earnout Payments is based on generating growth rates on the projected gross margins of Industrial Air and calculating the associated contingent payments based on achieving the earnout targets, which are reassessed each reporting period. In February 2025 and February 2026, the Company made payments in the amount of $3.0 million and $3.5 million, respectively, to the former owner of Industrial Air related to the First and Second Industrial Air Earnout Periods.

As a part of the total consideration for the Kent Island Transaction, the Company recognized $4.4 million in contingent consideration on the Kent Island Effective Date. The fair value of contingent Kent Island Earnout Payments is based on generating growth rates on the projected gross margins of Kent Island and calculating the associated contingent payments based on achieving the earnout targets, which are reassessed each reporting period. The Company determined the initial fair value of the Kent Island Earnout Payments based on the Monte Carlo Simulation method, which represented a Level 3 measurement. As of the Kent Island Effective Date, the Kent Island Earnout Payments associated with the Kent Island Transaction were valued utilizing a discount rate of 14.9%. The discount rate was calculated using the build-up method with a risk-free rate commensurate with the term of the Kent Island Earnout Payments based on the U.S. Treasury Constant Maturity Yield and certain metric risk premiums determined with reference to a long-term risk-free rate, a weighted average cost of capital and certain adjustments for operational leverage. In January 2026, the Company made a payment in the amount of $2.5 million to the former owner of Kent Island related to the First Kent Island Earnout Period.

As a part of the total consideration for the Consolidated Mechanical Transaction, the Company recognized $0.8 million in contingent consideration on the Consolidated Mechanical Effective Date. The fair value of contingent Consolidated Mechanical Earnout Payments is based on generating growth rates on the projected gross margins of Consolidated Mechanical and calculating the associated contingent payments based on achieving the earnout targets, which are reassessed each reporting period. The Company determined the initial fair value of the Consolidated Mechanical Earnout Payments based on the Monte Carlo Simulation method, which represented a Level 3 measurement. As of the Consolidated Mechanical Effective Date, the Consolidated Mechanical Earnout Payments associated with the Consolidated Mechanical Transaction were valued utilizing a discount rate of 10.4%. The discount rate was calculated using the build-up method with a risk-free rate commensurate with the term of the Consolidated Mechanical Earnout Payments based on the U.S. Treasury Constant Maturity Yield and certain metric risk premiums determined with reference to a long-term risk-free rate, a weighted average cost of capital and certain adjustments for operational leverage.

Based on the Company’s ongoing assessment of the fair value of contingent earnout liabilities, the Company recorded a net increase in the estimated fair value of such liabilities of $1.8 million, $3.8 million and $0.7 million for the years ended December 31, 2025, 2024 and 2023, respectively, which was presented in the acquisition-related retention expense and contingent consideration in the Company's consolidated statements of operations. The Company determined the fair value of the earnout payments by utilizing the Monte Carlo Simulation method, which represents a Level 3 measurement.

The following table presents the carrying values of the Company's contingent earnout payment obligations included in the accompanying consolidated balance sheets, which approximated fair value at December 31, 2025 and 2024.

(1) In February 2025, the Company made a $3.0 million payment to the former owner of Industrial Air related to the First IA Earnout Period.

(2) In October 2025, the Company made a $2.0 million payment to the former owner of ACME related to the Second ACME Earnout Period.

Interest Rate Swap

The fair value of the interest rate swap is determined using widely accepted valuation techniques and reflects the contractual terms of the interest rate swap including the period to maturity, and while there are no quoted prices in active markets, it uses observable market-based inputs, including interest rate curves and implied volatilities. The fair value analysis also considers a credit valuation adjustment to reflect nonperformance risk of both the Company and the single counterparty. The fair value of the interest rate contract has been determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). The variable cash payments (or receipts) are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves. The interest rate swap is classified as a Level 2 item within the fair value hierarchy. As of December 31, 2025 and 2024, the Company determined that the fair value of the interest rate swap was less than $0.1 million and approximately $0.2 million, respectively, and is recognized in other assets on the Company's consolidated balance sheets. For the years ended December 31, 2025, 2024 and 2023, the Company recognized a loss of $0.2 million, a gain of less than $0.1 million and a loss of $0.1 million, respectively, on its consolidated statements of operations associated with the change in fair value of the interest rate swap arrangement.

Note 10 –Earning per Share

Earnings per Share

The Company calculates earnings per share in accordance with ASC Topic 260 -Earnings Per Share (“EPS”). Basic earnings per share of the Company's common stock applicable to common stockholders is computed by dividing earnings applicable to common stockholders by the weighted-average number of shares of the Company's common stock outstanding and assumed to be outstanding. Diluted EPS assumes the dilutive effect of outstanding common stock warrants and shares issued in conjunction with the Company’s ESPP and RSUs, all using the treasury stock method.

The following table sets forth the computation of the basic and diluted earnings per share attributable to the Company's common stockholders for the years ended December 31, 2025, 2024 and 2023:

The following table summarizes the securities that were antidilutive, and therefore, were not included in the computations of diluted income per share of the Company's common stock:

Note 11 –Income Taxes

The Company is taxed as a C corporation and files income tax returns in the U.S. federal jurisdiction and in various state jurisdictions.

Provision for Income Taxes

The Company’s provision for income taxes related to continuing operations consists of the following:

The provision for income taxes for the years ended December 31, 2025, 2024 and 2023 resulted in effective tax rates on continuing operations of 19.7%,22.7%, and 26.1%, respectively.

As further described in Note 2, the Company has elected to retrospectively adopt the guidance in ASU 2023-09, Improvements to Income Tax Disclosures (Topic 740). The following table is a reconciliation of the U.S. federal statutory rate of 21% to the Company’s effective tax rate for the years ended December 31, 2025, 2024 and 2023 in accordance with the guidance in ASU 2023-09.

(1)The states that contributed to the majority (greater than 50%) of the tax effect in this category included: For fiscal year ended December 31, 2025, Florida, Michigan, and Massachusetts; for fiscal year ended December 31, 2024, Florida, Michigan, Pennsylvania and Tennessee; and for fiscal year ended December 31, 2023, Michigan, Florida and Massachusetts.

The Company is subject to taxation and files income tax returns in the U.S. federal jurisdiction and in various state jurisdictions. The Company’s 2022 and forward tax returns remain subject to examination by the U.S. federal taxing authorities. The Company’s 2021 and forward tax returns remain subject to examination by various state taxing authorities.

Applying the updated requirements in ASU 2023-09 on a retrospective basis, cash payments made for income taxes, net of refunds, were as follows:

(1)Income taxes paid, net of refunds, exceeded 5% of total income taxes paid, in the following jurisdictions.

• Jurisdiction below the threshold for the period presented.

Deferred Tax Assets (Liabilities)

Deferred tax assets and liabilities are recognized for temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The significant components of deferred tax assets and liabilities were as follows:

Management assesses the realizability of deferred tax assets based on whether it is more likely than not that such assets will be realized, which depends on the generation of sufficient future taxable income in the periods in which the related temporary differences reverse. In performing this assessment, the Company considers both positive and negative evidence. Based on this evaluation, management concluded that the Company’s deferred tax assets are more likely than not to be fully realized; accordingly, no valuation allowance was recorded as of December 31, 2025 and 2024.

As of December 31, 2025 and 2024, the Company hadno net operating loss carryforwards.

Liabilities for Uncertain Tax Positions

The Company hadno unrecognized tax benefits as of December 31, 2025 and 2024.

Note 12 –Operating Segments

As discussed in Note 1, the Company operates intwo segments (i) ODR, in which the Company performs owner direct projects and/or provides maintenance or service primarily on MEPC systems, and specialty contracting projects to existing buildings direct to, or assigned by, building owners or operators, and (ii) GCR, in which the Company generally manages new construction or renovation projects that involve primarily MEPC systems awarded to the Company by general contractors or construction managers. Segment information is prepared on the same basis the Company’s Chief Operating Decision Maker (“CODM”) reviews operating results for the purposes of allocating resources and assessing performance. The Company's CODM is comprised of its President and Chief Executive Officer and Executive Vice President and Chief Financial Officer.

In accordance with ASC Topic 280 –Segment Reporting, the Company has elected to aggregate all of the ODR work performed at its branches intoone ODR reportable segment and all of the GCR work performed at its branches intoone GCR reportable segment. All transactions between segments are eliminated in consolidation.

All of the Company’s identifiable assets are located in the United States, which is where the Company is domiciled. The Company does not have sales outside of the United States. For the years ended December 31, 2025, 2024 and 2023, no ODR or GCR segment customers accounted for 10% or more of the Company’s consolidated total revenue.

Consolidated segment information for the periods presented is as follows:

(1)Included within selling, general and administrative expenses was $7.0 million, $5.8 million and $4.9 million of non-cash stock-based compensation expense for the years ended December 31, 2025, 2024 and 2023, respectively.

The Company does not identify capital expenditures and total assets by segment in its internal financial reports due in part to the shared use of a centralized fleet of vehicles and specialized equipment.

Note 13 –Commitments and Contingencies

Legal. The Company is continually engaged in administrative proceedings, arbitrations, and litigation with owners, general contractors, suppliers, employees, former employees and other unrelated parties, all arising in the ordinary courses of business. The ultimate resolution of these contingencies could, individually or in the aggregate, be material to the consolidated financial statements. In the opinion of the Company’s management, the current belief is that the results of these actions will not have a material adverse effect on the financial position, results of operations, or cash flows of the Company.

Surety. The terms of its construction contracts frequently require that the Company obtain from surety companies, and provide to its customers, payment and performance bonds (“Surety Bonds”) as a condition to the award of such contracts. The Surety Bonds secure the Company’s payment and performance obligations under such contracts, and the Company has agreed to indemnify the surety companies for amounts, if any, paid by them in respect of Surety Bonds issued on its behalf. In addition, at the request of labor unions representing certain of the Company's employees, Surety Bonds are sometimes provided to secure obligations for wages and benefits payable to or for such employees. Public sector contracts require Surety Bonds more frequently than private sector contracts, and accordingly, the Company's bonding requirements typically increase as the amount of public sector work increases. As of December 31, 2025, the Company had approximately $156.6 million in surety bonds outstanding. The Surety Bonds are issued by surety companies in return for premiums, which vary depending on the size and type of bond.

Collective Bargaining Agreements. Many of the Company’s craft labor employees are covered by collective bargaining agreements. The agreements require the Company to pay specified wages, provide certain benefits and contribute certain amounts to multi-employer pension plans. If the Company withdraws from any of the multi-employer pension plans or if the plans were to otherwise become underfunded, the Company could incur additional liabilities related to these plans. Although the Company has been informed that some of the multi-employer pension plans to which it contributes have been classified as “critical” status, the Company is not currently aware of any significant liabilities related to this issue.

Self-insurance. The Company is substantially self-insured for workers’ compensation and general liability claims, in the view of the relatively high per-incident deductibles the Company absorbs under its insurance arrangements for these risks. The Company purchases workers’ compensation and general liability insurance under policies with per-incident deductibles of $250,000 per occurrence and a $4.6 million maximum aggregate deductible loss limit per year. Losses incurred over primary policy limits are covered by umbrella and excess policies up to specified limits with multiple excess insurers. The Company accrues for the unfunded portion of costs for both reported claims and claims incurred but not reported. The liability for unfunded reported claims and future claims is reflected on the consolidated balance sheets as current and non-current liabilities. The liability is determined by establishing a reserve for each reported claim on a case-by-case basis based on the nature of the claim and historical loss experience for similar claims plus an allowance for the cost of incurred but not reported claims. The current portion of the liability is included in accrued expenses and other current liabilities on the consolidated balance sheets. The non-current portion of the liability is included in other long-term liabilities on the consolidated balance sheets.

The Company is self-insured related to medical and dental claims under policies with annual per-claimant and annual aggregate stop-loss limits. The Company accrues for the unfunded portion of costs for both reported claims and claims incurred but not reported. The liability for unfunded reported claims and future claims is reflected on the consolidated balance sheets as a current liability in accrued expenses and other current liabilities.

The components of the self-insurance liability as of December 31, 2025 and 2024 are as follows:

The restricted cash balance represents an imprest cash balance set aside for the funding of workers' compensation and general liability insurance claims. This amount is replenished either when depleted or at the beginning of each month.

Note 14 -Leases

The Company leases real estate, vehicles and other equipment. The determination of whether an arrangement is, or contains, a lease is performed at the inception of the arrangement. Classification and initial measurement of the right-of-use asset and lease liability are determined at the lease commencement date. The Company elected the short-term lease measurement and recognition exemption; therefore, leases with an initial term of 12 months or less are not recorded on the consolidated balance sheets. Instead, the short-term leases are recognized in expense on a straight-line basis over the lease term.

The Company's arrangements include certain non-lease components such as common area and other maintenance for leased real estate, as well as mileage, fuel and maintenance costs related to leased vehicles. For all leased asset classes, the Company has elected to not separate non-lease components from lease components and will account for each separate lease component and non-lease component associated with the lease as a single lease component. The Company does not guarantee any residual value in its real estate lease agreements; however, certain vehicle lease arrangements may include residual value guarantees. There are no material restrictions or covenants imposed by lease arrangements. Real estate leases typically includeone or more options to extend the lease. The Company regularly evaluates the renewal options, and when they are reasonably certain of exercise, the Company includes the renewal period in its lease term. For the Company’s leased vehicles, the Company uses the interest rate implicit in its leases with the lessor to discount lease payments at the lease commencement date. When the implicit rate is not readily available, as is the case with the Company’s real estate leases, the Company uses quoted borrowing rates on its secured debt.

Related Party Lease Agreements. In conjunction with the closing of the Jake Marshall Transaction, the Company entered into an operating lease for certain land and facilities owned by a former member of JMLLC who was a full-time employee of the Company following the acquisition. The lease term isten years and includes an option to extend the lease fortwo successive periods oftwo years each through November 2035. Base rent for the term of the lease is $37,500 per month for the first five years with payment commencing on January 1, 2022. The fixed rent payment is escalated to $45,000 per month for years six through 10 of the lease term. Fixed rent payments for the extension term are increased from $45,000 by the percentage increase, if any, in the consumer price index from the lease commencement date. In addition, under the agreement, the Company is required to pay its share of estimated property taxes and operating expenses, both of which are variable lease expenses.

In conjunction with the closing of the ACME Transaction, the Company entered into an operating lease for certain land and facilities owned by a former member of ACME who was a full-time employee of the Company following the acquisition. The lease term of the lease runs through December 31, 2024 and included an option to extend the lease forone successive period ofone year through December 2025, which was not executed by the Company. Base rent for the term of the lease was $17,000 per month for the firstsix months with payment commencing on July 1, 2023. The fixed rent payment was escalated to $18,000 per month for the twelve month period ending December 31, 2024. In addition, under the agreement, the Company was required to pay its share of estimated property taxes and operating expenses, both of which are variable lease expenses. Following the expiration of the ACME facilities lease, ACME moved its operations to the aforementioned Jake Marshall leased facilities.

In conjunction with the closing of the Industrial Air Transaction, the Company entered into an operating lease for certain land and facilities owned by a former member of Industrial Air who was a full-time employee of the Company following the acquisition. The lease term of the lease runs through August 31, 2026 and includes an option to extend the lease fortwo successive periods ofthree years each through August 2032. Base rent for the term of the lease is $26,500 per month for the first thirty-three months with payment commencing on November 1, 2023. The fixed rent payment is escalated to $27,563 per month for the first three-year extension period ending August 31, 2029 and to $28,941 per month for the second three-year extension period ending on August 31, 2032. In addition, under the agreement, the Company is required to pay its share of estimated property taxes and operating expenses, both of which are variable lease expenses.

Southern California Sublease. In June 2021, the Company entered into a sublease agreement with a third party for the entire ground floor of its leased space in Southern California, consisting of 71,787 square feet. Under the terms of the sublease agreement, the sublessee is obligated to pay the Company base rent of approximately $0.6 million per year, which is subject to a 3.0% annual rent increase, plus certain operating expenses and other costs. The initial lease term commenced in September 2021 and continues through April 30, 2027. As of December 31, 2025, the Company remains obligated under the original lease for such office space and, in the event the sublessee of such office space fails to satisfy its obligations under the sublease, the Company would be required to satisfy its obligations directly to the landlord under such original lease.

In addition, during the first quarter of 2022, the Company entered into an amendment to the aforementioned sublease agreement, which, among other things, expanded the sublease premises to include the entire second floor of its leased space in Southern California, consisting of 16,720 square feet. Under the terms of the amended sublease agreement, the sublessee is obligated to pay the Company base rent of approximately $0.8 million per year, which is subject to a 3.0% annual rent increase, plus certain operating expenses and other costs. The amended sublease term commenced in March 2022 and continues through April 30, 2027. For each of the years ended December 31, 2025, 2024 and 2023, the Company recorded $1.2 million of income inselling, general and administrative expenses related to this sublease agreement.

The following table summarizes the lease amounts included in the Company’s consolidated balance sheets as of December 31, 2025 and 2024:

(1) Operating lease assets are recorded net of accumulated amortization of $17.9 million and $14.1 million at December 31, 2025 and 2024, respectively.

(2) Includes approximately $0.8 million and $0.9 million at December 31, 2025 and 2024, respectively, related to a below-market lease recognized as a result of the Industrial Air Transaction, which was recorded as an increase to the Company’s operating lease right-of-use assets on its consolidated balance sheets. The below-market lease will be amortized to amortization expense over the remaining lease term.

(3) Finance lease vehicle assets are recorded net of accumulated amortization of $8.2 million and $5.0 million at December 31, 2025 and 2024, respectively.

(4) Includes approximately $2.2 million and $2.4 million of net property assets associated with the Company's Pontiac Facility at both December 31, 2025 and 2024, respectively.

(5) Includes approximately $5.4 million associated with the Company's sale and leaseback financing transaction at both December 31, 2025 and 2024. See Note 7 — Debt for further detail.

The following table summarizes the lease costs included in the Company’s consolidated statements of operations for the years ended December 31, 2025, 2024 and 2023:

(1) Operating lease costs recorded in cost of revenue includes $0.7 million, $0.4 million and $0.4 million of variable lease costs for the years ended December 31, 2025, 2024 and 2023 respectively. In addition, $0.4 million, $0.4 million and $0.5 million of variable lease costs are included in selling, general and administrative expenses for the years ended December 31, 2025, 2024 and 2023, respectively. These variable costs consist of the Company’s proportionate share of operating expenses, real estate taxes and utilities.

(2) Finance lease costs recorded in cost of revenue includes $3.6 million, $4.0 million and $3.7 million of variable leases costs for the years ended December 31, 2025, 2024, and 2023 respectively. These variable lease costs consist of fuel, maintenance, and sales tax charges.

The future undiscounted minimum finance lease payments, as reconciled to the discounted minimum lease obligation indicated on the Company’s consolidated balance sheets within current and long-term debt, less interest, and under current and long-term operating leases, less imputed interest, as of December 31, 2025 were as follows (in thousands):

(1) Associated with the aforementioned related party leases entered into with former members of JMLLC, ACME and Industrial Air.

(2) Primarily associated with the aforementioned third-party sublease agreement.

(3) The financing component for finance lease obligations represents the interest component of finance leases that will be recognized as interest expense in future periods. The financing component for operating lease obligations represents the effect of discounting the lease payments to their present value.

The following is a summary of the lease terms and discount rates as of:

(1) Excludes the weighted average lease term and weighted average discount rate associated with the aforementioned sale-leaseback financing transaction, which has a Primary Term of 25 years and utilized an implicit rate of 11.11%. See Note 7 – Debt for further detail.

The following is a summary of other information and supplemental cash flow information related to finance and operating leases:

Note 15 –Retirement Plan

The Company maintains a 401(k) plan for eligible, participating employees. The Company contributes an amount equal to 100% of an employee’s salary reduction contributions up to 4% of such employee’s compensation in a given year, as defined by the plan and subject to IRS limitations. The Company’s mandatory contributions were $3.3 million for the year ended December 31, 2025, as compared to $2.8 million and $2.6 million for the years ended December 31, 2024 and 2023, respectively. The Company may make a discretionary profit-sharing contribution to the 401(k) plan in accordance with plan provisions. The Company has full discretion to determine whether to make such a contribution, and the amount of such contribution. In order to share in the profit-sharing contribution, employees must have satisfied the 401(k) Plan’s eligibility requirements and be employed on the last day of the year. Employees are not required to contribute any money to the 401(k) Plan in order to qualify for the Company profit sharing contribution. Any discretionary profit-sharing contribution would be divided among participants eligible to share in the contribution for the year in the same proportion that the participant’s pay bears to the total pay of all participants. This means the amount allocated to each eligible participant’s account would, as a percentage of pay, be the same. No discretionary profit-sharing contributions were made for the years ended December 31, 2025, 2024 or 2023.

Note 16 –Multiemployer Pension Plans

The Company participates in approximately 70 multiemployer pension plans (“MEPPs”) that provide pension benefits to certain union employees in accordance with various collective bargaining agreements (“CBAs”). As of December 31, 2025, approximately 46% of the Company’s employees are members of collective bargaining units. As one of many employers who are obligated to contribute to these MEPPs, the Company is responsible with the other participating employers for any unfunded pension liabilities. The Company’s contributions to a particular MEPP are established by the applicable CBAs; however, the Company’s required contributions to a MEPP may increase based on the funded status of the individual MEPP and the legal requirements of the Pension Protection Act of 2006 (the “PPA”), which requires substantially underfunded MEPPs to implement a funding improvement plan (“FIP”) or a rehabilitation plan (“RP”) to improve their funded status. Factors that could impact the funded status of a MEPP include, without limitation, investment performance, changes in participant demographics, a decline in the number of actively employed covered employees, a decline in the number of contributing employers, changes in actuarial assumptions and the utilization of extended amortization provisions. If a contributing employer stops contributing to a MEPP, the unfunded obligations of the MEPP may be borne by the remaining contributing employers. Assets contributed to an individual MEPP are pooled with contributions made by other contributing employers; the pooled assets will be used to provide benefits to the Company’s employees and the employees of the other contributing employers.

A FIP or RP requires a particular MEPP to adopt measures to correct its underfunded status. These measures may include, but are not limited to an increase in a contributing employer’s contribution rate, or changes to the benefits paid to retirees. In addition, the PPA requires that a 5% surcharge be levied on employer contributions for the first year commencing shortly after the date the employer receives notice that the MEPP is in critical status and a 10% surcharge on each succeeding year until a CBA is in place with terms and conditions consistent with the RP.

If a MEPP has unfunded pension liabilities, the Company could be obligated to make additional payments to a MEPP if the Company either ceases to have an obligation to contribute to the MEPP under a CBA or significantly reduces the Company’s contributions to the MEPP because they reduce the number of employees who are covered by the relevant MEPP for various reasons, including, but not limited to, layoffs or closure of a subsidiary. The amount of such payments (known as a complete or partial withdrawal liability) would equal the Company’s proportionate share of the MEPPs unfunded vested benefits. Based on the information available to the Company from the MEPPs, the Company believes that some of the MEPPs to which they contribute are underfunded and are in “critical” or “endangered” status as those terms are defined by the PPA. Due to uncertainty regarding future factors that could trigger withdrawal liability, as well as the absence of specific information regarding the MEPPs’ current financial situation, the Company is unable to determine (a) the amount and timing of any future withdrawal liability, if any, and (b) whether the Company’s participation in these MEPPs could have a material adverse impact on its financial condition, results of operations or liquidity.

The nature and diversity of the Company’s business may result in volatility of the amount of contributions to a particular MEPP for any given period. That is because, in any given market, the Company could be working on a significant project and/or projects, which could result in an increase in the direct labor force and a corresponding increase in contributions to the MEPP(s) dictated by the applicable CBA. When that particular project(s) finishes and is not replaced, the level of direct labor would also decrease, as would the level of contributions to the particular MEPP(s). Additionally, the level of contributions to a particular MEPP could also be affected by the terms of the CBA, which could require at a particular time, an increase in the contribution rate and/or surcharges.

Total contributions to the various union construction industry MEPP, welfare, training and other benefits programs in accordance with the CBAs were $40.8 million for the year ended December 31, 2025, as compared to $28.2 million and $31.8 million for the years ended December 31, 2024 and 2023, respectively. Of these amounts, total contributions to MEPPs accounted for $14.3 million, $10.3 million and $11.6 million for the years ended December 31, 2025, 2024 and 2023, respectively.

The following table presents the MEPPs in which the Company participates. Additionally, this table also lists the PPA Zone Status for MEPPs as the critical status (red zone-less than 65% funded), the endangered status (yellow-less than 80% funded), the seriously endangered status (orange-less than 80% funded and projects a credit balance deficit within seven years) or neither critical or endangered status (green-greater than 80% funded). The zone status represents the most recent available information for the respective MEPP, which in certain circumstances is 2024 for the 2025 year. These dates may not correspond with the Company’s calendar year contributions. The zone status is based on information received from the MEPPs and is certified by the MEPPs’ actuaries. The “FIP/RP Status” column indicates MEPPs for which a financial improvement plan (FIP) or rehabilitation plan (RP) has been adopted or implemented.

(1)This information was obtained from the respective plan’s Form 5500 (“Forms”) for the most current available filing. These dates may not correspond with the Company’s fiscal year contributions. The above-noted percentages of contributions are based upon disclosures contained in the plans’ Forms. Those Forms, among other things, disclose the names of individual participating employers whose annual contributions account for more than 5% of the aggregate annual amount contributed by all participating employers for a plan year.

Accordingly, if the annual contribution of two or more of the Company’s subsidiaries each accounted for less than 5% of such contributions, but in the aggregate accounted for in excess of 5% of such contributions, that greater percentage is not available and accordingly is not disclosed.

(2) Funding status based off of the prior year funding notice as the current year’s funding notice was not available prior to the filing of this Annual Report on Form 10-K.

Note 17 –Management Incentive Plans

The Company initially adopted the Omnibus Incentive Plan on July 20, 2016 for the purpose of: (a) encouraging the profitability and growth of the Company through short-term and long-term incentives that are consistent with the Company’s objectives; (b) giving participants an incentive for excellence in individual performance; (c) promoting teamwork among participants; and (d) giving the Company a significant advantage in attracting and retaining key employees, directors and consultants. To accomplish such purposes, the Omnibus Incentive Plan, and such subsequent amendments to the Omnibus Incentive Plan, provides that the Company may grant options, stock appreciation rights, restricted shares, RSUs, performance-based awards (including performance-based restricted shares and restricted stock units), other share-based awards, other cash-based awards or any combination of the foregoing.

Following the approval of the 2023 Amended and Restated Omnibus Incentive Plan, the Company has reserved 3,050,000 shares of its common stock for issuance. The number of shares issued or reserved pursuant to the Omnibus Incentive Plan will be adjusted by the plan administrator, as they deem appropriate and equitable, as a result of stock splits, stock dividends, and similar changes in the Company’s common stock. In connection with the grant of an award, the plan administrator may provide for the treatment of such award in the event of a change in control. Historically, all awards are made in the form of shares only.

Effective January 1, 2025, the Company adopted a Severance and Change in Control Plan (the “Severance Plan”). The purpose of the Severance Plan is to provide financial support to a group of senior-level executives of the Company following a qualifying termination of employment, consistent with the Company’s values and culture and to help attract and retain highly qualified employees essential to the Company’s success.

In April 2025, the Board of Directors approved certain amendments to the 2023 Amended and Restated Omnibus Incentive Plan to make certain changes related to the treatment of death, disability, retirement and reduction in force as it relates to the plan participants. The amendments were acted upon by the Company's stockholders at the Annual Meeting held on June 11, 2025.

Service-Based Awards

The Company grants service-based stock awards in the form of RSUs. Service-based RSUs granted to executives, employees and non-employee directors vest ratably, on an annual basis, over three years and in the case of certain awards to non-employee directors, overone year. The grant date fair value of the service-based awards was equal to the closing market price of the Company’s common stock on the date of grant. For the years ended December 31, 2025, 2024 and 2023, the Company recognized $2.2 million, $2.1 million and $1.5 million of non-cash stock-based compensation expense related to outstanding service-based RSUs, respectively.

The following table summarizes the Company’s service-based RSU activity:

Performance-Based Awards

The Company has granted performance-based restricted stock units (“PRSUs”) under which shares of the Company’s common stock may be earned based on the Company’s performance compared to defined metrics. The number of shares earned under a performance award may vary from zero to 150% of the target shares awarded, based upon the Company’s performance compared to the metrics. The metrics used for the grant are determined by the Company’s Compensation Committee of the Board of Directors and are based on internal measures such as the achievement of certain predetermined adjusted EBITDA and EBITDA margin performance goals generally over athree-year period.

The Company recognizes non-cash stock-based compensation expense for these awards over the vesting period based on the projected probability of achievement of the performance conditions as of the end of each reporting period during the performance period and may periodically adjust the recognition of such expense, as necessary, in response to any changes in the Company’s forecasts with respect to the performance conditions. For the years ended December 31, 2025, 2024 and 2023, the Company recognized $3.3 million and $3.6 million and $3.4 million, respectively, of non-cash stock-based compensation expense related to outstanding PRSUs. All unvested PRSU awards as of December 31, 2025 are related to awards granted in fiscal years 2023 and 2024.

The following table summarizes the Company’s PRSU activity:

(1) Performance-based awards covering the three year period ended December 31, 2022 were paid out in the first quarter of 2023 based on the approval of the Company's Compensation Committee. The performance factor during the measurement period used to determine compensation payouts was 136.13% of the pre-defined metric target of 100%, which resulted in a positive performance factor adjustment and the issuance of 32,327 of additional awards associated with the original grant.

(2) Performance-based awards covering the three-year period ended December 31, 2023 were paid out in the first quarter of 2024 based on the approval of the Company's Compensation Committee. The performance factor during the measurement period used to determine compensation payouts was 134.3% of the pre-defined metric target of 100%, which resulted in a positive performance factor adjustment and the issuance of 54,067 shares of the Company's common stock as additional awards associated with the original grant.

(3) Performance-based awards covering the three-year period ended December 31, 2024 were paid out in the first quarter of 2025 based on the approval of the Company's Compensation Committee. The performance factor during the measurement period used to determine compensation payouts was 150% of the pre-defined metric target of 100%, which resulted in a positive performance factor adjustment and the issuance of 106,471 shares of the Company's common stock as additional awards associated with the original grant.

Market-Based Awards

During the first quarter of 2025, the Company granted market-based RSUs (“MRSUs”) to certain employees that vest based on the Company's total shareholder return (“TSR”) relative to the TSR of the Russell 2000 Index over athree-year performance period. The number of shares that ultimately vest can range from 0% to 150% of the target award, based on the Company's TSR percentile ranking relative to the Russell 2000 Index constituents during the performance period.

Because vesting is subject to a market condition, the grant date fair value of these awards was estimated using a Monte Carlo simulation model. The assumptions used in the model included expected volatility for the Company and the Russell 2000 Index, risk-free interest rates, expected dividend yields, and the correlation between the Company's stock and the Russell 2000 Index. The grant date fair value is expensed over the requisite three-year performance period using a straight-line method, as long as the employee remains employed during the performance period. For the year ended December 31, 2025, the Company recognized $1.4 million of non-cash stock-based compensation expense related to outstanding MRSUs. No MRSUs were outstanding during the years ended December 31, 2024 and 2023.

Stock-Based Compensation Expense

Total recognized non-cash stock-based compensation expense amounted to $7.0 million, $5.8 million and $4.9 million for the years ended December 31, 2025, 2024 and 2023, respectively. The aggregate fair value as of the vest date of RSUs that vested during the years ended December 31, 2025, 2024 and 2023 was $29.7 million, $16.9 million and $3.8 million, respectively. Total unrecognized stock-based compensation expense related to unvested RSUs which are probable of vesting amounted to $6.3 million at December 31, 2025. These costs are expected to be recognized over a weighted average period of 1.66 years.