Mayville Engineering Company, Inc.

(in thousands except share amounts, per share data, years and ratios)

Note 1. Basis of presentation

The interim unaudited Condensed Consolidated Financial Statements of Mayville Engineering Company, Inc. and subsidiaries (MEC, the Company, we, our, us or similar terms) presented here have been prepared in accordance with the accounting principles generally accepted in the United States of America (GAAP) and with instructions to Form 10-Q and Article 10 of Regulation S-X. They reflect all adjustments which are, in the opinion of management, necessary for a fair presentation of the results of operations and financial position for the interim unaudited periods presented. All intercompany balances and transactions have been eliminated in consolidation.

Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted. These interim unaudited Condensed Consolidated Financial Statements should be read in conjunction with the Company’s consolidated financial statements and notes thereto for the year ended December 31, 2024, included in the Company’s Annual Report on Form 10-K. A summary of the Company’s significant accounting policies is included in the Company’s 2024 financial statements in the Annual Report on Form 10-K. The Company followed these policies in preparation of the interim unaudited Condensed Consolidated Financial Statements except for new accounting pronouncements adopted as described below.

Nature of Operations

MEC is a leading U.S.-based, vertically-integrated, value-added manufacturing partner providing a full suite of manufacturing solutions from concept to production, including design, prototyping and tooling, fabrication, aluminum extrusion, coating, assembly and aftermarket components. Our customers operate in diverse end markets, including heavy- and medium-duty commercial vehicles, construction & access equipment, powersports, data center & critical power, agriculture, military and other end markets. Founded in 1945 and headquartered in Milwaukee, Wisconsin, we are a leading Tier I U.S. supplier of highly engineered components to original equipment manufacturer (OEM) customers with leading positions in their respective markets. The Company maintains 27 facilities, of which 26 are in operation, located in Arkansas, Illinois, North Carolina, Michigan, Mississippi, Ohio, Pennsylvania, Virginia, and Wisconsin. Our engineering expertise and technical know-how allow us to add value through every product redevelopment cycle.

Ourone operating segment focuses on producing metal components that are used in a broad range of heavy- and medium-duty commercial vehicles, construction & access equipment, powersports, data center & critical power, agricultural, military and other products.

Recent Accounting Pronouncements

In September 2025, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2025-06,* Intangibles – Goodwill and Other-Internal-Use Software,amending Accounting Standards Codification (ASC) 350.*The amendment removes all references to prescriptive and sequential software development stages. In addition, the amendment also requires consideration whether there is significant uncertainty associated with the development activities of the software during evaluation of probable-to-complete recognition threshold. ASU 2025-06 is effective for interim and annual periods beginning after December 15, 2027. Entities may adopt the guidance using either a prospective approach (including a modified transition approach) or retrospective approach. Early adoption is permitted. The Company is evaluating the potential impact of this guidance on the consolidated financial statements.

In November 2024, the FASB issued ASU 2024-03,* Expense Disaggregation Disclosures,*amending ASC 220,*Income Statement – Reporting Comprehensive Income.*The amendment requires an entity to provide a disclosure within the financial statement footnotes showing the disaggregation of certain expenses included in relevant expense captions on the consolidated income statement, with a qualitative description of the amounts that are not separately disaggregated quantitatively. The guidance also requires disclosure of the total amount of selling expenses and, in annual reporting periods, an entity’s definition of selling expenses. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026 and for interim periods beginning after December 15, 2027. The guidance is applied on a prospective basis, with a retrospective option and allows for early adoption. The Company is evaluating the potential impact of this guidance on the consolidated financial statements.

In December 2023, the FASB issued ASU 2023-09,* Improvements to Income Tax Disclosures*, amending ASC 740,*Income Taxes.*The amendment is intended to enhance the transparency about income tax information through improvements to income tax disclosures primarily related to the rate reconciliation and income taxes paid information. The amendments require that on an annual basis, entities disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold. In addition, the amendments require that entities disclose additional information about income taxes paid as well as additional disclosures of pretax income and income tax expense and remove the requirement to disclose certain items that are no longer considered cost beneficial or relevant. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. The Company will adopt this standard in the fourth quarter of 2025 and we believe this standard will not have a material impact on our consolidated financial statements.

Note 2. Acquisition

On July 1, 2025, the Company acquired 100% of the membership interests of Accu-Fab, LLC (Accu-Fab). The acquisition was consummated in accordance with the terms of the Purchase Agreement dated May 23, 2025, among the Company, Accu-Fab, and Tide Rock YieldCo, LLC (the Seller). The purchase price of the acquisition was $140,500, subject to customary adjustments for the amount of cash, indebtedness, net working capital, and certain expenses of Accu-Fab as of the closing. The acquisition of Accu-Fab was structured as a stock purchase for accounting purposes. As of the closing of the acquisition, after taking into account the estimated adjustments, the Company paid the Seller a total net consideration of $141,185. The Company financed the acquisition by borrowing under its amended and restated credit agreement as described in Note 4 - Debt in the Notes to the Condensed Consolidated Financial Statements.

With locations in Wheeling, Illinois and Raleigh, North Carolina, Accu-Fab is a vertically integrated manufacturing partner providing technology driven, cutting edge metal fabrication solutions to large OEMs. Accu-Fab offers value-added services including design, engineering, sheet metal fabrication and integration, and specialized finishing. The acquisition enhances MEC’s strategic position by broadening its customer base and accelerating its entry into the rapidly growing data center & critical power infrastructure end markets.

The Company accounted for the acquisition using the acquisition method of accounting in accordance with ASC 805 -Business Combinations, with MEC being the acquiring entity. Transaction costs related to the acquisition were expensed as incurred within other selling, general, and administrative expenses and totaled $887 and $3,265 for the three and nine months ended September 30, 2025, respectively. The net sales and operating income of Accu-Fab, which is consolidated in MEC’s financial statements presented herein, since July 1, 2025 were $21,246 and $4,225, respectively, for the three months and nine months ended September 30, 2025.

The aggregate purchase price has been allocated to the assets acquired and liabilities assumed based on their preliminary estimated fair values as of the acquisition date. The estimate of the excess purchase price over the preliminary estimated fair value of net tangible assets acquired was allocated to identifiable intangible assets and goodwill. The Company engaged an independent third party to assist with the identification and valuation of the acquired assets, including intangible assets. Management makes significant estimates and assumptions when determining the fair value of assets acquired and liabilities assumed. These estimates include, but are not limited to, discount rates, projected future net sales, projected future expected cash flows, useful lives, attrition rates, and growth rates. These measures are based on significant Level 3 inputs not observable in the market.

The following table is a summary of the assets acquired, liabilities assumed, and net cash consideration paid for the acquisition of Accu-Fab. The allocation is considered preliminary and subject to finalization within one year from the acquisition date:

Inventory was valued at its estimated fair value, which is defined as expected sales price, less costs to sell, plus a reasonable margin for selling effort. The valuation resulted in an inventory fair value step-up of $591 and was fully expensed and reflected in cost of sales on the Condensed Consolidated Statement of Comprehensive Income (Loss) during the three and nine months ended September 30, 2025.

Property, plant and equipment was valued at its estimated fair value using the cost, market and sales comparison approaches. The valuation resulted in a property, plant and equipment fair value step-up of $5,326. Depreciation on property, plant and equipment is computed on a straight-line basis over the estimated useful life of the respective assets.

The Company also recorded $67,000 of customer relationships intangible assets and $2,200 of non-compete agreement intangible assets. The purchase price allocated to these assets was based on management’s forecasted cash inflows and outflows and the multi-period excess earnings method for customer relationships and the with and without method for the non-compete agreements. Amortization expense related to these intangible assets is recorded on a straight-line basis and reflected in amortization of intangible assets on the Condensed Consolidated Statements of Comprehensive Income (Loss).

The purchase price of Accu-Fab exceeded the preliminary estimated fair value of identifiable net assets and accordingly, the difference was allocated to goodwill, all of which is tax deductible. Goodwill will be tested for impairment at least annually, or more frequently if events or changes in circumstances indicate that the asset may be impaired, in accordance with ASC 350 –Intangibles. The goodwill recognized primarily reflects expected synergies from integrating Accu-Fab’s operations into the Company’s existing manufacturing platform, the assembled workforce, and other intangible assets that do not meet the criteria for separate recognition under ASC 805.

The Company believes that the information gathered to date provides a reasonable basis for estimating the fair values of assets acquired and liabilities assumed; however, the purchase price allocations are preliminary as we continue to gather the necessary information to finalize our fair value estimates and provisional amounts. Provisional amounts include items related to working capital

adjustments, intangible assets, indemnification of assets and liabilities and deferred taxes. The net working capital true-up remains subject to final agreement with the Seller and may result in future adjustments to the purchase price. During the three months ended September 30, 2025, the Company did not adjust the purchase price related to working capital adjustments.

The Company has recorded preliminary estimates for the items noted in the preceding paragraph and will record adjustments, if any, to the preliminary amounts upon finalization of the respective valuations. Such changes are not expected to be significant. The Company expects to complete the purchase price allocation as soon as practicable but no later than one year from the acquisition date.

Pro Forma Financial Information (Unaudited)

In accordance with ASC 805, the following unaudited pro forma combined results of operations have been prepared and presented to give effect to the Accu-Fab acquisition as if it had occurred on January 1, 2024, the beginning of the comparable period, applying certain assumptions and pro forma adjustments. These pro forma adjustments primarily relate to the estimated depreciation expense associated with the fair value of the acquired property, plant, and equipment, amortization of identifiable intangible assets, interest expense related to additional debt needed to fund the acquisition, and the tax impact of these adjustments. Additionally, the pro forma adjustments exclude non-recurring expenses related to transaction costs, which were expensed as incurred, and include the sale of stepped-up inventory. The unaudited pro forma consolidated results are provided for illustrative purposes only, are not indicative of the Company’s actual consolidated results of operations or consolidated financial position and do not reflect any revenue and operating synergies or cost savings that may result from the acquisition.

Note 3. Select balance sheet data

Inventory

Inventories are stated at the lower of cost, determined on the first-in, first-out method, or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. Work-in-process and finished goods are valued at production costs consisting of material, labor, and overhead.

Inventories as of September 30, 2025 and December 31, 2024 consist of:

Property, plant and equipment

Property, plant and equipment as of September 30, 2025 and December 31, 2024 consist of:

Depreciation expense was $8,012 and $7,748 for the three months ended September 30, 2025 and 2024, respectively, and $23,630 and $22,927 for the nine months ended September 30, 2025 and 2024, respectively.

Additionally, the Company completed the closure of its Wautoma, WI manufacturing facility during the fourth quarter of the prior year period. The net amount of property, plant and equipment associated with the facility was $1,402, which is classified in assets held for sale on the Condensed Consolidated Balance Sheets as of September 30, 2025 and December 31, 2024.

Goodwill

The following table sets forth the changes in the carrying amount of goodwill as of September 30, 2025. The carrying value of goodwill was increased by $47,639 during the nine months ended September 30, 2025, related to the acquisition of Accu-Fab.

Intangible Assets

The following is a listing of definite-lived intangible assets, the useful lives in years (amortization period) and accumulated amortization as of September 30, 2025 and December 31, 2024:

Additionally, the Company reported an indefinite lived non-amortizable brand name asset with a balance of $3,811 as of September 30, 2025 and December 31, 2024.

Changes in definite-lived intangible assets between December 31, 2024 and September 30, 2025 consist of:

Amortization expense was $3,125 and $1,733 for the three months ended September 30, 2025 and 2024, respectively, and $6,591 and $5,200 for the nine months ended September 30, 2025 and 2024.

Future amortization expense is expected to be as followed:

Note 4. Debt

Bank Revolving Credit Notes

On June 28, 2023, and as last amended on June 26, 2025, we entered into an amended and restated credit agreement (the Credit Agreement) with certain lenders and Wells Fargo Bank, National Association, as administrative agent (the Agent). The Credit Agreement provides for a $350,000 revolving credit facility, with a letter of credit sub-facility, and a swingline facility in an aggregate amount of $25,000. All amounts borrowed under the credit agreement mature on June 28, 2028.

The Credit Agreement contains usual and customary negative covenants for agreements of this type, including, but not limited to, restrictions on our ability to, subject to certain exceptions, create, incur or assume indebtedness; create, incur, assume or suffer to exist liens; make certain investments; allow our subsidiaries to merge or consolidate with another entity; make certain asset dispositions; pay certain dividends or other distributions to shareholders; enter into transactions with affiliates; enter into sale leaseback transactions; and exceed the limits on annual capital expenditures. The Credit Agreement also requires us to satisfy certain financial covenants, including a minimum consolidated interest coverage ratio of 3.00 to 1.00 as well as a consolidated total leverage ratio not to exceed 4.00 to 1.00 (which was modified as of July 1, 2025, from 3.50 to 1.00 in connection with the acquisition of Accu-Fab).

The Company entered into an amendment (First Amendment) to the Credit Agreement on June 26, 2025. The First Amendment increased the amount of total allowable borrowings under the revolving credit facility to $350,000 from $250,000, by exercising the previously available $100,000 accordion feature. All other material terms of the credit agreement, including applicable interest rates, remained unchanged.

The Company incurred financing costs of $793 associated with executing the First Amendment, with the short-term and long-term balance of $264 and $462, respectively, recorded in prepaid expenses and other current assets and other long-term assets in the Condensed Consolidated Balance Sheets. These deferred financing costs will be amortized over the remaining duration of the agreement.

At September 30, 2025, our consolidated total leverage ratio was 3.47 to 1.00 as compared to a covenant maximum of 4.00 to 1.00 under the Credit Agreement.

At September 30, 2025, our consolidated interest coverage ratio was 6.23 to 1.00 as compared to a covenant minimum of 3.00 to 1.00 under the Credit Agreement.

Under the Credit Agreement, interest is payable quarterly at the adjusted secured overnight financing rate (SOFR) plus an applicable margin based on the current consolidated total leverage ratio (which may be adjusted for certain reserve requirements), plus 1.25% to 2.75% depending on the current consolidated total leverage ratio. Under certain circumstances, we may not be able to pay interest based on SOFR. If that happens, we will be required to pay interest at the Base Rate, which is the sum of the higher of (i) the Prime Rate (as publicly announced by the Agent from time to time), (ii) the Federal Funds Rate plus 0.50%, and (iii) Adjusted Term SOFR for a one-month tenor in effect on such dayplus 1.00%. The interest rate was 5.39% and 6.55% as of September 30, 2025 and December 31, 2024, respectively. Additionally, the agreement has a fee on the average daily unused portion of the aggregate unused revolving commitments. This fee was 0.30% and 0.25% as of September 30, 2025 and December 31, 2024, respectively.

The Company was in compliance with all financial covenants of its credit agreements as of September 30, 2025 and December 31, 2024. The amount borrowed on the revolving credit notes was $211,858 and $79,725 as of September 30, 2025 and December 31, 2024, respectively.

Other Debt

Additionally, the Company has a Fond du Lac County and Fond du Lac Economic Development Corporation term note (Fond du Lac Term Note). The Fond du Lac Term Note is secured by a security agreement, payable in annual installments of $500 plus interest at 2.00% and is due in full in December 2028. The balance outstanding as of September 30, 2025 and December 31, 2024 was $1,875. The short-term and long-term balance of $500 and $1,375, respectively, are recorded in other current liabilities and other long-term liabilities in the Condensed Consolidated Balance Sheets, respectively.

Note 5. Leases

The Company has real property operating leases for office and manufacturing space. Operating leases for the Company’s personal property consist of leases for office equipment, vehicles, forklifts and storage tanks for bulk gases. The Company recognizes a right-of-use (ROU) asset and a lease liability for operating leases based on the net present value of future minimum lease payments. Lease expense for the Company’s operating leases is recognized on a straight-line basis over the lease term, including renewal periods that are considered reasonably certain. The Company has not elected to recognize right-of-use assets or lease liabilities for leases with a term of twelve months or less.

The Company has finance leases for equipment used throughout its office and manufacturing facilities. The Company recognizes an ROU asset and a lease liability for finance leases based on the net present value of future minimum lease payments.

Lease expense for the Company’s finance leases is comprised of the amortization of the ROU asset and interest expense recognized based on the effective interest method.

Variable lease expense is related to certain of the Company’s real property leases and personal property leases, and it generally consists of property tax and insurance components that are for the benefit of the lessor (real property leases) and variable overage fees (personal property leases) that are remitted as part of the Company’s lease payments.

The components of lease expense were as follows:

The lease related supplemental cash flow information is as follows:

Note 6. Employee stock ownership plan

Under the Mayville Engineering Company, Inc. Employee Stock Ownership Plan (ESOP), the Company can make annual discretionary contributions to the trust for the benefit of eligible employees in the form of cash or shares of common stock of the Company subject to the Board of Directors’ approval. The Company recordedno ESOP expense for the three and nine months ended September 30, 2025 and 2024.

As of January 1, 2025, the Company amended the plan reducing the distribution period from three years to full distribution on the annual distribution date of the year following separation from the Company.

Additionally, as of January 1, 2025, the in-service diversification percentage allowed increased from 25% at age 50 with 10 years of service to 50% and at age 55 with 10 years of service, the percentage allowed increased from 50% to 75%.

At various times following death, disability, retirement, termination of employment or the exercise of diversification rights, an ESOP participant is entitled to receive their ESOP account balance in accordance with various distribution methods as permitted under the policies adopted by the ESOP.

As of September 30, 2025 and December 31, 2024, the ESOP shares consisted of 1,903,861 and 3,474,467 in allocated shares, respectively.

Note 7. Retirement plans

The Mayville Engineering Company, Inc. 401(k) Plan (the 401(k) Plan) covers substantially all employees meeting certain eligibility requirements. The 401(k) Plan is a defined contribution plan and is intended for eligible employees to defer tax-free contributions to save for retirement. Employees may contribute up to 50% of their eligible compensation to the 401(k) Plan, subject to the limits of Section 401(k) of the Internal Revenue Code.

The Company provides a 50% match for employee contributions, up to 6%. For the three months ended September 30, 2025 and 2024, the Company’s employer match expense was $884 and $609, respectively. Total employer match expense for the nine months ended September 30, 2025 and 2024 was $2,631 and $2,585, respectively.

Note 8. Income taxes

On a quarterly basis, the Company estimates its effective tax rate for the full fiscal year and records a quarterly income tax provision based on the anticipated rate and adjusted for discrete taxable events that may occur in the quarter. As the year progresses, the Company will refine its estimate based on facts and circumstances by each tax jurisdiction.

Income tax benefit was $707 and $941, and the effective tax rate (ETR) was 20.90% and 20.05% for the three and nine months ended September 30, 2025, respectively. Our ETR is different from the expected tax rate due to state taxes, non-deductible items, research and development credits and excess tax expense associated with stock-based compensation items. The year-to-date rate includes the recognition of unfavorable discrete items.

For the three and nine months ended September 30, 2024, income tax expense was estimated at $100 and $2,532 and the ETR was 3.24% and 20.21%, respectively.

On July 4, 2025, U.S. enacted H.R. 1 “A bill to provide for reconciliation pursuant to Title II of H. Con. Res 14,” commonly referred to as the One Big Beautiful Bill Act. We have evaluated the provisions of H.R. 1 and concluded that they do not have a material impact on the Condensed Consolidated Financial Statements.

Uncertain Tax Positions

Based on the Company’s evaluation, there is one unrecognized tax benefit requiring recognition in its financial statements as of September 30, 2025. Any interest and penalties related to uncertain tax positions are recorded in income tax expense (benefit) on the Condensed Consolidated Statements of Comprehensive Income (Loss). The entire balance of unrecognized tax benefits as of September 30, 2025, if recognized, would affect the Company’s effective tax rate.

The Company files income tax returns in the United States federal jurisdiction and in various state and local jurisdictions. Federal tax returns for tax years beginning January 1, 2021, and state tax returns for the years beginning January 1, 2020, are open for examination.

Note 9. Commitments and contingencies

Litigation

From time to time, the Company may be involved in various claims and lawsuits, both for and against the Company, arising in the normal course of business. Although the results of litigation and claims cannot be predicted with certainty, in management’s

opinion, either the likelihood of loss is remote, or any reasonably possible loss associated with the resolution of such proceedings is not expected to have a material adverse impact on the condensed consolidated financial statements.

Note 10. Deferred compensation

The Mayville Engineering Company Deferred Compensation Plan is available for certain employees designated to be eligible to participate by the Company and approved by the Board of Directors. Eligible employees may elect to defer a portion of their compensation for any plan year and the deferral cannot exceed 50% of the participant’s base salary and may include the participant’s annual short-term cash incentive up to 100%. The participants’ election must be made prior to the first day of the plan year.

An employer contribution will be made for each participant to reflect the amount of any reduced allocations to the ESOP and/or 401(k) employer contributions due solely to the participant’s deferral amounts, as applicable. In addition, a discretionary amount may be awarded to a participant by the Company.

Deferrals are assumed to be invested in an investment vehicle based on the options made available to the participant (which does not include Company stock).

The deferred compensation plan provides benefits payable upon separation of service or death. Payments are to be made 180 days after date of separation from service, either in a lump-sum payment or up to five annual installments as elected by the participant when the participant first elects to defer compensation.

The deferred compensation plan is non-funded, and all future contributions are unsecured in that the employees have the status of a general unsecured creditor of the Company and the agreements constitute a promise by the Company to make benefit payments in the future. During the three and nine months ended September 30, 2025, eligible employees elected to defer compensation of $87 and $762, respectively. Eligible employees elected to defer compensation of $96 and $544 for the three and nine months ended September 30, 2024, respectively. As of September 30, 2025 and December 31, 2024, the short-term portion accrued for all benefit years less than twelve months under this plan was $1,397 and $251, respectively, which is included within bonuses and deferred compensation on the Condensed Consolidated Balance Sheets. As of September 30, 2025 and December 31, 2024, the long-term portion accrued for all benefit years greater than twelve months under this plan was $4,672 and $4,719. These amounts include the initial deferral of compensation and were adjusted for changes in the value of investment options chosen by the participants. Total expense for the deferred compensation plan for the three months ended September 30, 2025 and 2024 was $281 and $204, respectively. Total expense for the deferred compensation plan for the nine months ended September 30, 2025 and 2024 was $591 and $489, respectively. These expenses are included in bonuses and deferred compensation on the Condensed Consolidated Statements of Comprehensive Income (Loss). Additionally, the Company made cash distributions of $253 and $286 for the nine months ended September 30, 2025 and 2024, respectively.

Note 11. Self-Funded insurance

The Company is self-funded for the medical benefits provided to its employees and their dependents. Healthcare costs are expensed as incurred and are based upon actual claims paid, reinsurance premiums, administration fees, and estimated unpaid claims. The Company has an aggregate stop loss limit to mitigate risk. Expenses related to this contract were $5,314 and $6,104 for the three months ended September 30, 2025 and 2024, respectively and $13,086 and $18,655 for the nine months ended September 30, 2025 and 2024. An estimated accrued liability of $836 and $1,184 was recorded as of September 30, 2025 and December 31, 2024, respectively, for estimated unpaid claims and is included within other current liabilities on the Condensed Consolidated Balance Sheets.

Note 12. Segments

The Company operates as a single reporting unit and single reporting segment, and is managed on a consolidated basis. The Company derives revenue from its customers by providing value-added manufacturing solutions ranging from concept to production, including prototyping and tooling, production fabrication, coating, assembly and aftermarket components. The accounting policies of the Company'sone operating segment are the same as those described in the summary of significant accounting policies. The Company’s chief operating decision maker (CODM) is regularly provided with and assesses performance for itsone operating

segment with only the consolidated expenses and net income (loss) as presented in the Condensed Consolidated Statements of Comprehensive Income (Loss).

The CODM uses these performance measures to evaluate the Company's profitability, deciding whether to reinvest profits into the segment or into other parts of the entity, such as acquisitions or to buy back Company common stock and monitor budget versus actual results.

All sales are generated and all assets are located within the United States and the business activities are managed at a consolidated level.

The Company’s President and Chief Executive Officer is the CODM.

Note 13. Fair value of financial instruments

Fair value provides information on what the Company may realize if certain assets were sold or might pay to transfer certain liabilities based upon an exit price. Financial assets and liabilities that are measured and reported at fair value are classified into a three-level hierarchy that prioritizes the inputs used in the valuation process. A financial instrument’s categorization within the valuation hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The hierarchy is based on the observability and objectivity of the pricing inputs as follows:

The following table lists the Company’s financial assets and liabilities accounted for at fair value by the fair value hierarchy:

Fair value measurements for the Company’s cash and cash equivalents are classified based upon Level 1 measurements because such measurements are based upon quoted market prices in active markets for identical assets.

Accounts receivable, accounts payable, long-term debt and accrued liabilities are recorded in the Condensed Consolidated Balance Sheets at cost and approximate fair value.

Deferred compensation liabilities are recorded at amounts due to participants at the time of deferral. Deferrals are invested in an investment vehicle based on the options made available to the participant, considered to be Level 1 or Level 2 on the fair value hierarchy, with the current balance all as Level 1. The change in fair value is recorded in the bonuses and deferred compensation line

item on the Condensed Consolidated Statements of Comprehensive Income (Loss). The short-term and long-term balances due to participants are reflected on the bonuses and deferred compensation and deferred compensation, less current portion line items, respectively, on the Condensed Consolidated Balance Sheets.

The Company’s non-financial assets such as goodwill, intangible assets and property, plant, and equipment are re-measured at fair value when there is an indication of impairment and adjusted only when an impairment charge is recognized. As of September 30, 2025, there wasno impairment recognized for the year.

Note 14. Earnings Per Share

The Company computes earnings per share in accordance with ASC Topic 260,Earnings per Share. In accordance with ASC 260, outstanding options will be considered to have been exercised and outstanding as of the beginning of the period if the average market price of the common stock during the period exceeds the exercise price of the options (they are “in the money”), and the assumed exercise of the options do not have an anti-dilutive impact on earnings per share.

A reconciliation of basic and diluted net income (loss) per share attributable to the Company were as follows:

There wereno options in the money that were excluded in the computation of diluted earnings per share for the three and nine months ended September 30, 2025 and 2024 that had an anti-dilutive impact on earnings per share.

Note 15. Revenue Recognition

Contract Assets and Contract Liabilities

The Company has contract assets and contract liabilities, which are included in tooling in progress and other current liabilities on the Condensed Consolidated Balance Sheets, respectively. Contract assets primarily consist of capitalized costs related to customer-owned tooling contracts, wherein the Company has not yet met performance obligations. Contract liabilities include deferred tooling revenue, where the performance obligation was not met. The performance obligation is satisfied when the tooling is completed and the customer signs off through the Product Part Approval Process or other documented customer acceptance. Cost of goods sold is recognized and released from the balance sheet when control of the tooling promised under contract is transferred to the customer.

The Company’s contracts with customers are short-term in nature; therefore, revenue is typically recognized, billed and collected within a 12-month period. The following table reflects the changes in our contract assets and liabilities during the nine months ended September 30, 2025:

During the nine months ended September 30, 2025, revenue recognized from deferred revenue that was recorded as a contract liability at the beginning of 2025 was $2,755. During the nine months ended September 30, 2024, revenue recognized from deferred revenue that was recorded as a contract liability at the beginning of 2024 was$2,620.

Disaggregated Revenue

The following tables represent a disaggregation of revenue by product category and end market:

In connection with the acquisition of Accu-Fab, the Company added a new end market category, data center & critical power to its revenue disaggregation. As a result, revenue previously reported within other has been reclassified to data center & critical power for all periods presented. Specifically, $4,658 and $13,139 of revenue for the three and nine months ended September 30, 2024, respectively, were reclassified from other to data center & critical power to conform to the current period presentation.

Note 16. Concentration of major customers

The following customers accounted for 10% or greater of the Company’s recorded net sales or net trade receivables:

Note 17. Stock-based compensation

The Mayville Engineering Company, Inc. 2019 Omnibus Incentive Plan provided the Company the ability to grant monetary payments based on the value of its common stock, up to 2,000,000 shares.

On April 20, 2021, shareholders of the Company approved an amendment to the 2019 Omnibus Incentive Plan increasing the number of shares of common stock authorized for issuance by 2,500,000 shares.

The total number of shares of the Company’s common stock still available for issuance under the 2019 Omnibus Incentive Plan as of September 30, 2025 is 1,684,137.

The Company recognizes stock-based compensation using the fair value provisions prescribed by ASC 718,Compensation – Stock Compensation. Accordingly, compensation costs for awards of stock-based compensation settled in shares are determined based on the fair value of the stock-based instrument at the time of grant and are recognized as expense over the vesting period of the stock-based instrument. Our stock-based compensation consists of stock options, restricted stock units (RSUs) and performance stock units (PSUs). For all types of units, fair value is equivalent to the adjusted closing stock price at the date of the grant. The Black-Scholes option pricing model is utilized to determine fair value for stock options.

Cancellations and forfeitures are accounted for as incurred.

Stock-based compensation expense was $845 and $1,352 for the three months ended September 30, 2025 and 2024, respectively, and $2,953 and $3,847 for the nine months ended September 30, 2025 and 2024, respectively. The Company reports stock-based compensation within bonuses and deferred compensation in the Condensed Consolidated Statements of Comprehensive Income (Loss).

There wereno stock options granted by the Company to employees during the three and nine months ended September 30, 2025 and 2024. Stock option grants expire 10 years subsequent to the grant date. Stock-based compensation expense related to stock options is calculated by estimating the fair value of non-qualified stock options at the time of grant and is amortized over the stock options’ vesting period. During the nine months ended September 30, 2025,113,700 options vested with a weighted average strike price of $15.99. There wereno stock options exercised during the three months ended September 30, 2025. For the nine months ended September 30, 2025,125,363 options were exercised with a weighted average strike price of $11.69. As of September 30, 2025,335,713 options remained outstanding with a weighted average strike price of $14.50 and a weighted average contractual life of 9.95 years. During the three and nine months ended September 30, 2025,86,542 options were forfeited with a weighted average strike price of $16.57.

The Company granted 12,404 and 4,611 RSUs, during the three months ended September 30, 2025 and 2024, respectively. The Company granted 335,541 and 427,171 RSUs, inclusive of 53,721 and 55,962 director awards during the nine months ended September 30, 2025 and 2024, respectively. The RSUs granted to employees vest ratably over athree-year period beginning the subsequent year to the anniversary of the grant date and director awards vest the subsequent year to the grant date.

No PSUs were granted by the Company to employees during the three months ended September 30, 2025 and 2024. The Company granted 169,062 and 110,710 PSUs during the nine months ended September 30, 2025 and 2024, respectively. PSUs are earned based on the achievement of pre-determined financial performance goals at the end of athree-year performance measurement period. The applicable performance period varies for each grant year.

The performance goals for the PSUs granted in 2025 are weighted 50% on the 3-year average of the Company’s Return on Invested Capital (“ROIC”) from 2025 to 2027 and 50% on the Company’s 2027 adjusted EBITDA target. The performance goals for the PSUs granted in 2024 are weighted 50% on the 3-year average of the Company’s ROIC from 2024 to 2026 and 50% on the Company’s 2026 adjusted EBITDA target. ROIC represents net operating profit after taxes divided by invested capital for the represented period. Adjusted EBITDA represents net income before interest expense, provision (benefit) for income taxes, depreciation, amortization, stock-based compensation expense, legal costs due to the former fitness customer and adjusted for items to be determined unusual in nature or infrequent in occurrence for the performance period, as approved by the Compensation Committee. The number of earned PSUs can range from 50% (threshold) to 200% (maximum) of the target award, with no PSUs earned for performance below the threshold level.

Note 18. Common Equity

At September 30, 2025 the authorized stock of the Company consisted of 75,000,000 shares of common stock without par value.

Changes in outstanding common shares are summarized as follows:

Note 19. Restructuring

On August 5, 2025, the Company initiated a restructuring plan (the Plan) designed to reduce fixed costs and optimize its operational footprint. The Plan provides for the consolidation ofthree warehouses andone manufacturing facility into the Company’s other facilities and is expected to be completed by December 31, 2026.

The Company expects to incur aggregate charges of between $5,000 and $7,000 in total restructuring costs, which includes approximately $5,000 for equipment relocation and footprint optimization and approximately $1,000 in asset write-downs and related charges. Total restructuring charges incurred during the three months ended September 30, 2025 were $559, recorded in cost of sales in the Condensed Consolidated Statements of Comprehensive Income (Loss). The Company expects to incur additional charges under the Plan in future periods as implementation progresses. Restructuring charges during the three and nine months ended September 30, 2025, were as follows: