SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Investments in Equity Investees	Investments in Equity Investees We use the equity method to account for our investments in joint ventures, affiliated companies and alliances in which we have the ability to exercise significant influence, generally represented by equity ownership or partnership equity of at least 20 percent but not more than 50 percent. Generally, under the equity method, original investments in these entities are recorded at cost and subsequently adjusted by our share of equity in income or losses after the date of acquisition. Equity in income or losses of each investee is recorded according to our level of ownership; if losses accumulate, we record our share of losses until our investment has been fully depleted. If our investment has been fully depleted, we recognize additional losses only when we are the primary funding source. We eliminate (to the extent of our ownership percentage) in our Consolidated Financial Statements the profit in inventory held by our equity method investees that has not yet been sold to a third-party. Dividends received from equity method investees reduce the amount of our investment when received and do not impact our earnings. Our investments are classified as “Investments and advances related to equity method investees” in our Consolidated Balance Sheets. Our share of the results from joint ventures, affiliated companies and alliances is reported in our Consolidated Statements of Net Income as “Equity, royalty and interest income from investees” and is reported net of all applicable income taxes. Our foreign equity investees are presented net of applicable foreign income taxes in our Consolidated Statements of Net Income.
Use of Estimates in the Preparation of the Consolidated Financial Statements	Use of Estimates in the Preparation of the Consolidated Financial Statements Preparation of financial statements requires management to make estimates and assumptions that affect reported amounts presented and disclosed in our Consolidated Financial Statements. Significant estimates and assumptions in these Consolidated Financial Statements require the exercise of judgment and are used for, but not limited to, estimates of future cash flows and other assumptions associated with goodwill and long-lived asset impairment tests, useful lives for depreciation and amortization, warranty programs, restructuring costs, income taxes, deferred tax valuation allowances, contingencies and allowances for doubtful accounts. Due to the inherent uncertainty involved in making estimates, actual results reported in future periods may be different from these estimates.
Revenue From Contracts with Customers	Revenue From Contracts with Customers Revenue Recognition Sales of Products We sell to customers either through long-term arrangements or standalone purchase orders. Our long-term arrangements generally do not include committed volumes until underlying purchase orders are issued. Typically, we recognize revenue on the products we sell at a point in time, in accordance with shipping terms or other contractual arrangements. All related shipping and handling costs are accrued at the time the related performance obligation has been satisfied. Our sales arrangements may include the collection of sales and other similar taxes that are then remitted to the related taxing authority. We have elected to present the amounts collected for these taxes net of the related tax expense rather than presenting them as additional revenue. We grant credit limits and terms to customers based upon traditional practices and competitive conditions. Typical terms vary by market, but payments are generally due in 60 days or less from invoicing for most of our product sales. Sales Incentives We provide various sales incentives to both our distribution network and OEM customers. These programs are designed to promote the sale of our products or encourage the usage of our products by OEM customers. When there is uncertainty surrounding these sales incentives, we may reduce the amount of revenue we recognize under a contract through an incentive accrual. When the uncertainty has been resolved the accrual will be adjusted accordingly. Sales incentives primarily fall into three categories: •Aftermarket rebates; •Volume and growth rebates; and •Marketing Development Fund (“MDF”). For aftermarket rebates, we provide incentives to promote sales to certain dealers and end-markets. These rebates are typically paid on a quarterly, or more frequent, basis. At the time of the sale, we consider the expected amount of these rebates when determining the overall transaction price. Estimates are adjusted at the end of each month or quarter based sales and historical experience. For volume and growth rebates, we provide certain customers with rebate opportunities for attaining specified volumes during a particular quarter or year. We consider the expected amount of these rebates at the time of the original sale as we determine the sales revenue. We update our assessment of the amount of rebates that will be earned on a monthly or quarterly basis based on our best estimate of the volume levels the customer will reach during the measurement period. For MDF’s, these are funds to support our customers primarily for business development, marketing and advertising programs, promotional items jointly developed, dealer incentives and partnering programs. Depending on the agreement, the funds are accrued for and paid on a quarterly basis, annual basis, or as agreed with those customers receiving these funds. Sales Returns The initial determination of the sales revenue may also be impacted by product returns. Rights of return do not exist for the majority of our sales other than for quality issues. We do offer certain return rights in our aftermarket business, where some aftermarket customers are permitted to return a small amount of filters each year. An estimate of future returns is accounted for at the time of sale as a reduction in the overall sales revenue based on historical return rates.
Foreign Currency Transactions and Translation	Foreign Currency Transactions and Translation We translate assets and liabilities of foreign entities to U.S. dollars, where the local currency is the functional currency, at month-end exchange rates. We translate income and expenses to U.S. dollars using weighted-average exchange rates. We record adjustments resulting from translation in a separate component of accumulated other comprehensive loss and include the adjustments in net income only upon sale, loss of controlling financial interest or liquidation of the underlying foreign investment. Foreign currency transaction gains and losses are included in net income. For foreign entities where the U.S. dollar is the functional currency, including those operating in highly inflationary economies when applicable, we remeasure non-monetary balances and the related income statement amounts using historical exchange rates.
Income Tax Accounting	Income Tax Accounting We determine our income tax expense using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax effects of temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Future tax benefits of net operating loss and credit carryforwards are also recognized as deferred tax assets. We evaluate the recoverability of our deferred tax assets each quarter by assessing the likelihood of future profitability and available tax planning strategies that could be implemented to realize our net deferred tax assets. A valuation allowance is recorded to reduce the tax assets to the net value management believes is more likely than not to be realized. In the event our operating performance deteriorates, future assessments could conclude that a larger valuation allowance will be needed to further reduce the deferred tax assets. In addition, we operate within multiple taxing jurisdictions and are subject to tax audits in these jurisdictions. These audits can involve complex issues, which may require an extended period of time to resolve. We accrue for the estimated additional tax and interest that may result from tax authorities disputing uncertain tax positions. We believe we made adequate provisions for income taxes for all years that are subject to audit based upon the latest information available. Our income tax provision was prepared following the separate return method, which applies Accounting Standards Codification (“ASC”) 740 to the standalone financial statements of each member of the combined group as if the group member were a separate and standalone enterprise. Due to this treatment, tax transactions included in the Consolidated Financial Statements of the Parent may not be included in the separated Consolidated Financial Statements of the Company. Similarly, there may be certain tax attributes within the Consolidated Financial Statements of the Company that would not be found in the Consolidated Financial Statements and tax returns of the Parent. Examples of such items include net operating losses, tax credits carry forwards and valuation allowances, which may exist in the standalone financial statements but not in the Parent’s Consolidated Financial Statements. The international tax framework introduced by the Organization for Economic Co-operation and Development under its Pillar Two initiative includes a global minimum tax of 15 percent. Legislation adopting these provisions has been enacted in certain jurisdictions where the Company operates and is effective for the Company's 2024 fiscal year. The Company has assessed this legislation and the Pillar Two provisions do not have a material impact on the Company’s tax expense.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of bank checking accounts and money market accounts. Atmus considers all highly liquid investments with original maturities of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents are carried at cost, which approximates fair value.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable represent amounts billed to customers and not yet collected or amounts that have been earned but may not be billed until the passage of time and are recorded when the right to consideration becomes unconditional. Trade accounts receivable are recorded at the invoiced amount, which approximates net realizable value and generally do not bear interest. The allowance for doubtful accounts is our best estimate of the amount of expected credit losses in our existing accounts receivable. We determine the allowance based on our historical collection experience and by performing an analysis of our accounts receivable in light of the current economic environment. This estimate of expected losses reflects those losses expected to occur over the contractual life of the receivable. We review our allowance for doubtful accounts at least quarterly, and more frequently as needed. In addition, when necessary, we provide an allowance for the full amount of specific accounts deemed to be uncollectible. Account balances are charged off against the allowance in the period in which we determine that it is probable the receivable will not be recovered.
Inventories	Inventories Our inventories are stated at the lower of cost or net realizable value. As of December 31, 2024 and 2023, approximately 30.3% and 32.1%, respectively, of our inventories were valued using the last-in, first-out (LIFO) cost method. The cost of other inventories is generally valued using the first-in, first-out (FIFO) cost method. Our inventories include estimates for adjustments related to annual physical inventory results and for inventory cost changes under the LIFO cost method. Due to significant movements of partially-manufactured components and parts between manufacturing plants, we do not internally measure, nor do our accounting systems provide, a meaningful segregation between raw materials and work-in-process.
Property, Plant and Equipment	Property, Plant and Equipment We record property, plant and equipment at cost, inclusive of finance lease assets, with the adoption of ASC 842. We depreciate the cost of the majority of our property, plant and equipment using the straight-line method with depreciable lives ranging from 20 to 40 years for buildings and 3 to 15 years for machinery, equipment and fixtures. Finance lease asset amortization is recorded in depreciation expense. We expense normal maintenance and repair costs as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets We review our long-lived assets for possible impairment whenever events or circumstances indicate that the carrying value of an asset or asset group may not be recoverable. We assess the recoverability of the carrying value of the long-lived assets at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. An impairment of a long-lived asset or asset group exists when the expected future pre-tax cash flows (undiscounted and without interest charges) estimated to be generated by the asset or asset group is less than its carrying value. If these cash flows are less than the carrying value of such asset or asset group, an impairment loss is measured based on the difference between the estimated fair value and carrying value of the asset or asset group. Assumptions and estimates used to estimate cash flows in the evaluation of impairment and the fair values used to determine the impairment are subject to a degree of judgment and complexity. Any changes to the assumptions and estimates resulting from changes in actual results or market conditions from those anticipated may affect the carrying value of long-lived assets and could result in a future impairment charge.
Leases	Leases We determine if an arrangement contains a lease in whole or in part at the inception of the contract. Right-of-use (“ROU”) assets represent our right to use an underlying asset for the lease term while lease liabilities represent our obligation to make lease payments arising from the lease. All leases greater than 12 months result in the recognition of a ROU asset and a liability at the lease commencement date based on the present value of the lease payments over the lease term. As most of our leases do not provide the information required to determine the implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. This rate is determined considering factors such as the lease term, our credit standing and the economic environment of the location of the lease. We use the implicit rate when readily determinable. Our lease terms include all non-cancelable periods and may include options to extend (or to not terminate) the lease when it is reasonably certain that we will exercise that option. Leases that have a term of 12 months or less at the commencement date are expensed on a straight-line basis over the lease term and do not result in the recognition of an asset or a liability. Lease expense for operating leases is recognized on a straight-line basis over the lease term. Lease expense for finance leases is generally front-loaded as the finance lease ROU asset is depreciated on a straight-line basis, but interest expense on the liability is recognized utilizing the interest method that results in more expense during the early years of the lease. We have lease agreements with lease and non-lease components, primarily related to real estate, vehicle and information technology (“IT”) assets. For vehicle and real estate leases, we account for the lease and non-lease components as a single lease component. For IT leases, we allocate the payment between the lease and non-lease components based on the relative value of each component.
Goodwill	Goodwill We have the option to first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value as a basis for determining whether it is necessary to perform an annual quantitative goodwill impairment test. We have elected this option for our reporting unit. In addition, the carrying value of goodwill must be tested for impairment on an interim basis in certain circumstances where impairment may be indicated. When we are required or opt to perform the quantitative impairment test, the fair value of our reporting unit is estimated with either the market approach or the income approach using a discounted cash flow model. Our income approach method uses a discounted cash flow model in which cash flows anticipated over several periods, plus a terminal value at the end of that time horizon, are discounted to their present value using an appropriate rate of return. The discounted cash flow model requires us to make projections of revenue, gross margin, operating expenses, working capital investment and fixed asset additions for our reporting unit over a multi-year period. Additionally, management must estimate a weighted-average cost of capital, which reflects a market rate, for our reporting unit for use as a discount rate. The discounted cash flows are compared to the carrying value of the reporting unit and, if less than the carrying value, the difference is recorded as a goodwill impairment loss. In addition, we also perform a sensitivity analysis to determine how much our forecasts can fluctuate before the fair value of a reporting unit would be lower than its carrying amount. We perform the required procedures as of the end of our fiscal third quarter. Changes in our projections or estimates, a deterioration of our operating results and the related cash flow effect or a significant increase in the discount rate could decrease the estimated fair value of our reporting unit and result in a future impairment of goodwill.
Warranty	Warranty We estimate and record a liability for standard warranty programs at the time our products are sold. Our estimates are based on historical experience and reflect management’s best estimates of expected costs at the time products are sold and subsequent adjustment to those expected costs when actual costs differ. As a result of the uncertainty surrounding the nature and frequency of product campaigns, the liability for such campaigns is recorded when we commit to a recall action or when a recall becomes probable and estimable, which generally occurs when it is announced. We review and assess the liability for these programs on a quarterly basis.
Research, Development and Engineering	Research, Development and Engineering Our research, development and engineering programs are focused on product improvements, product extensions, innovations and cost reductions for our customers. Research, development and engineering expenditures include salaries, contractor fees, building costs, utilities, testing, technical IT, administrative expenses and allocation of corporate costs and are expensed, net of contract reimbursements, when incurred.
Segment Information	Segment Information We operate our business as one operating segment and also one reportable segment based on the manner in which we review and evaluate operating performance. The types of products from which revenue is derived are the same as those described in the description of the business section and the accounting policies are the same as those described in the summary of significant accounting policies. The operating results are regularly reviewed by Atmus’ chief operating decision maker on a consolidated basis. The chief operating decision maker is our Chief Executive Officer. The chief operating decision maker assesses performance for our business and decides how to allocate resources based on net income that also is reported on the income statement as consolidated net income and is regularly provided with consolidated expense information from the income statement. The measurement of business assets is reported on the balance sheet as total consolidated assets. The chief operating decision maker uses net income predominately in the annual budget and forecasting process. The chief operating decision maker considers budget-to-actual in deciding whether to reinvest profit into the operating segment or for other entity initiatives, such as acquisitions, paying dividends, or share repurchases. The chief operating decision maker also uses the profit or loss measure for determining compensation of certain employees.
Stock-Based Compensation	Stock-Based Compensation We maintain a share-based compensation plan, which authorizes the granting of various equity-based incentives, including restricted stock units (“RSU”s) and performance share units (“PSU”s). Stock compensation expense is generally amortized on a straight line basis over the service period during which awards are expected to vest, generally three years. RSUs are typically granted to selected employees on an annual basis and vest over three years. Dividend equivalents are paid during the vesting period. The fair value of our RSUs and other stock-based awards is measured at the market price of our Common Stock on the grant date. PSUs vest based on varying performance, market and service conditions. The fair value of our PSUs is measured at the market price of our Common Stock on the grant date. The final award may equal 0-200 percent of the target grant, based on our actual performance during the vesting period. Forfeitures are estimated on the grant date for all of our stock-based compensation awards.
Pension and other Postretirement Benefits	Pensions and other Postretirement Benefits Atmus provides a range of benefits, including pensions, postretirement and post-employment benefits to eligible current and former employees, of which certain of our employees participate. For purposes of Atmus’ Consolidated Financial Statements, participation in Atmus plans are treated as single-employer plans. See Note 13, Pensions and Other Postretirement Benefits, for more information.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which requires a public entity to disclose significant segment expenses and other segment items on an annual and interim basis and provide in interim periods all disclosures about a reportable segment’s profit or loss and assets that are currently required annually. Additionally, it requires a public entity to disclose the title and position of the Chief Operating Decision Maker (“CODM”). The ASU does not change how a public entity identifies its operating segments, aggregates them, or applies the quantitative thresholds to determine its reportable segments. The new standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. A public entity should apply the amendments in this ASU retrospectively to all prior periods presented in the financial statements. We adopted this standard in the fourth quarter of 2024 and it did not have a material impact on our disclosures and no impacts to our results of operations, cash flows and financial condition. Income Taxes (Topic 740): Improvements to Income Tax Disclosures In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, that requires entities to disclose additional information about federal, state, and foreign income taxes primarily related to the income tax rate reconciliation and income taxes paid. The new standard also eliminates certain existing disclosure requirements related to uncertain tax positions and unrecognized deferred tax liabilities. The guidance is effective for our fiscal year ending December 31, 2025, with early adoption permitted. The guidance does not affect recognition or measurement in our consolidated financial statements. We expect this ASU to only impact our disclosures with no impacts to our results of operations, cash flows and financial condition. Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which requires disclosure of certain costs and expenses on an interim and annual basis in the notes to the consolidated financial statements. The guidance is effective for annual reporting periods beginning after December 15, 2026 and interim periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The guidance is to be applied either prospectively to financial statements issued for reporting periods after the effective date or retrospectively to any or all prior periods presented in the financial statements. We are currently evaluating the potential impact of adopting this new guidance on our consolidated financial statements and related disclosures.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2024

We use the equity method to account for our investments in joint ventures, affiliated companies and alliances in which we have the ability to exercise significant influence, generally represented by equity ownership or partnership equity of at least 20 percent but not more than 50 percent. Generally, under the equity method, original investments in these entities are recorded at cost and subsequently adjusted by our share of equity in income or losses after the date of acquisition. Equity in income or losses of each investee is recorded according to our level of ownership; if losses accumulate, we record our share of losses until our investment has been fully depleted. If our investment has been fully depleted, we recognize additional losses only when we are the primary funding source. We eliminate (to the extent of our ownership percentage) in our Consolidated Financial Statements the profit in inventory held by our equity method investees that has not yet been sold to a third-party. Dividends received from equity method investees reduce the amount of our investment when received and do not impact our earnings. Our investments are classified as “Investments and advances related to equity method investees” in our Consolidated Balance Sheets. Our share of the results from joint ventures, affiliated companies and alliances is reported in our Consolidated Statements of Net Income as “Equity, royalty and interest income from investees” and is reported net of all applicable income taxes. Our foreign equity investees are presented net of applicable foreign income taxes in our Consolidated Statements of Net Income.

Use of Estimates in the Preparation of the Consolidated Financial Statements

Preparation of financial statements requires management to make estimates and assumptions that affect reported amounts presented and disclosed in our Consolidated Financial Statements. Significant estimates and assumptions in these Consolidated Financial Statements require the exercise of judgment and are used for, but not limited to, estimates of future cash flows and other assumptions associated with goodwill and long-lived asset impairment tests, useful lives for depreciation and amortization, warranty programs, restructuring costs, income taxes, deferred tax valuation allowances, contingencies and allowances for doubtful accounts. Due to

the inherent uncertainty involved in making estimates, actual results reported in future periods may be different from these estimates.

Revenue From Contracts with Customers

Revenue Recognition Sales of Products

We sell to customers either through long-term arrangements or standalone purchase orders. Our long-term arrangements generally do not include committed volumes until underlying purchase orders are issued. Typically, we recognize revenue on the products we sell at a point in time, in accordance with shipping terms or other contractual arrangements. All related shipping and handling costs are accrued at the time the related performance obligation has been satisfied.

Our sales arrangements may include the collection of sales and other similar taxes that are then remitted to the related taxing authority. We have elected to present the amounts collected for these taxes net of the related tax expense rather than presenting them as additional revenue.

We grant credit limits and terms to customers based upon traditional practices and competitive conditions. Typical terms vary by market, but payments are generally due in 60 days or less from invoicing for most of our product sales.

Sales Incentives

We provide various sales incentives to both our distribution network and OEM customers. These programs are designed to promote the sale of our products or encourage the usage of our products by OEM customers. When there is uncertainty surrounding these sales incentives, we may reduce the amount of revenue we recognize under a contract through an incentive accrual. When the uncertainty has been resolved the accrual will be adjusted accordingly. Sales incentives primarily fall into three categories:

•Aftermarket rebates;

•Volume and growth rebates; and

•Marketing Development Fund (“MDF”).

For aftermarket rebates, we provide incentives to promote sales to certain dealers and end-markets. These rebates are typically paid on a quarterly, or more frequent, basis. At the time of the sale, we consider the expected amount of these rebates when determining the overall transaction price. Estimates are adjusted at the end of each month or quarter based sales and historical experience.

For volume and growth rebates, we provide certain customers with rebate opportunities for attaining specified volumes during a particular quarter or year. We consider the expected amount of these rebates at the time of the original sale as we determine the sales revenue. We update our assessment of the amount of rebates that will be earned on a monthly or quarterly basis based on our best estimate of the volume levels the customer will reach during the measurement period.

For MDF’s, these are funds to support our customers primarily for business development, marketing and advertising programs, promotional items jointly developed, dealer incentives and partnering programs. Depending on the agreement, the funds are accrued for and paid on a quarterly basis, annual basis, or as agreed with those customers receiving these funds.

Sales Returns

The initial determination of the sales revenue may also be impacted by product returns. Rights of return do not exist for the majority of our sales other than for quality issues. We do offer certain return rights in our aftermarket business, where some aftermarket customers are permitted to return a small amount of filters each year. An estimate of future returns is accounted for at the time of sale as a reduction in the overall sales revenue based on historical return rates.

Foreign Currency Transactions and Translation

We translate assets and liabilities of foreign entities to U.S. dollars, where the local currency is the functional currency, at month-end exchange rates. We translate income and expenses to U.S. dollars using weighted-average exchange rates. We record adjustments resulting from translation in a separate component of accumulated other comprehensive loss and include the adjustments in net income only upon sale, loss of controlling financial interest or liquidation of the underlying foreign investment.

Foreign currency transaction gains and losses are included in net income. For foreign entities where the U.S. dollar is the functional currency, including those operating in highly inflationary economies when applicable, we remeasure non-monetary balances and the related income statement amounts using historical exchange rates.

Income Tax Accounting

We determine our income tax expense using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax effects of temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Future tax benefits of net operating loss and credit carryforwards are also recognized as deferred tax assets. We evaluate the recoverability of our deferred tax assets each quarter by assessing the likelihood of future profitability and available tax planning strategies that could be implemented to realize our net deferred tax assets. A valuation allowance is recorded to reduce the tax assets to the net value management believes is more likely than not to be realized. In the event our operating performance deteriorates, future assessments could conclude that a larger valuation allowance will be needed to further reduce the deferred tax assets. In addition, we operate within multiple taxing jurisdictions and are subject to tax audits in these jurisdictions. These audits can involve complex issues, which may require an extended period of time to resolve. We accrue for the estimated additional tax and interest that may result from tax authorities disputing uncertain tax positions. We believe we made adequate provisions for income taxes for all years that are subject to audit based upon the latest information available.

Our income tax provision was prepared following the separate return method, which applies Accounting Standards Codification (“ASC”) 740 to the standalone financial statements of each member of the combined group as if the group member were a separate and standalone enterprise. Due to this treatment, tax transactions included in the Consolidated Financial Statements of the Parent may not be included in the separated Consolidated Financial Statements of the Company. Similarly, there may be certain tax attributes within the Consolidated Financial Statements of the Company that would not be found in the Consolidated Financial Statements and tax returns of the Parent. Examples of such items include net operating losses, tax credits carry forwards and valuation allowances, which may exist in the standalone financial statements but not in the Parent’s Consolidated Financial Statements.

The international tax framework introduced by the Organization for Economic Co-operation and Development under its Pillar Two initiative includes a global minimum tax of 15 percent. Legislation adopting these provisions has been enacted in certain jurisdictions where the Company operates and is effective for the Company's 2024 fiscal year. The Company has assessed this legislation and the Pillar Two provisions do not have a material impact on the Company’s tax expense.

Cash and Cash Equivalents

Cash and cash equivalents consist of bank checking accounts and money market accounts. Atmus considers all highly liquid investments with original maturities of three months or less at the time of purchase to be cash equivalents. Cash and cash equivalents are carried at cost, which approximates fair value.

Accounts Receivable and Allowance for Doubtful Accounts

Trade accounts receivable represent amounts billed to customers and not yet collected or amounts that have been earned but may not be billed until the passage of time and are recorded when the right to consideration becomes unconditional. Trade accounts receivable are recorded at the invoiced amount, which approximates net realizable value and generally do not bear interest. The allowance for doubtful accounts is our best estimate of the amount of expected credit losses in our existing accounts receivable. We determine the allowance based on our historical collection experience and by performing an analysis of our accounts receivable in light of the current economic environment. This estimate of expected losses reflects those losses expected to occur over the contractual life of the receivable. We review our allowance for doubtful accounts at least quarterly, and more frequently as needed. In addition, when necessary, we provide an allowance for the full amount of specific accounts deemed to be uncollectible. Account balances are charged off against the allowance in the period in which we determine that it is probable the receivable will not be recovered.

Inventories

Our inventories are stated at the lower of cost or net realizable value. As of December 31, 2024 and 2023, approximately 30.3% and 32.1%, respectively, of our inventories were valued using the last-in, first-out (LIFO) cost method. The cost of other inventories is generally valued using the first-in, first-out (FIFO) cost method. Our inventories include estimates for adjustments related to annual physical inventory results and for inventory cost changes under the LIFO cost method. Due to significant movements of partially-manufactured components and parts between manufacturing plants, we do not internally measure, nor do our accounting systems provide, a meaningful segregation between raw materials and work-in-process.

Property, Plant and Equipment

We record property, plant and equipment at cost, inclusive of finance lease assets, with the adoption of ASC 842. We depreciate the cost of the majority of our property, plant and equipment using the straight-line method with depreciable lives ranging from 20 to 40 years for buildings and 3 to 15 years for machinery, equipment and fixtures. Finance lease asset amortization is recorded in depreciation expense. We expense normal maintenance and repair costs as incurred.

Impairment of Long-Lived Assets

We review our long-lived assets for possible impairment whenever events or circumstances indicate that the carrying value of an asset or asset group may not be recoverable. We assess the recoverability of the carrying value of the long-lived assets at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. An impairment of a long-lived asset or asset group exists when the expected future pre-tax cash flows (undiscounted and without interest charges) estimated to be generated by the asset or asset group is less than its carrying value. If these cash flows are less than the carrying value of such asset or asset group, an impairment loss is measured based on the difference between the estimated fair value and carrying value of the asset or asset group. Assumptions and estimates used to estimate cash flows in the evaluation of impairment and the fair values used to determine the impairment are subject to a degree of judgment and complexity. Any changes to the assumptions and estimates resulting from changes in actual results or market conditions from those anticipated may affect the carrying value of long-lived assets and could result in a future impairment charge.

Leases

We determine if an arrangement contains a lease in whole or in part at the inception of the contract. Right-of-use (“ROU”) assets represent our right to use an underlying asset for the lease term while lease liabilities represent our obligation to make lease payments arising from the lease. All leases greater than 12 months result in the recognition of a ROU asset and a liability at the lease commencement date based on the present value of the lease payments over the lease term. As most of our leases do not provide the information required to determine the implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. This rate is determined considering

factors such as the lease term, our credit standing and the economic environment of the location of the lease. We use the implicit rate when readily determinable.

Our lease terms include all non-cancelable periods and may include options to extend (or to not terminate) the lease when it is reasonably certain that we will exercise that option. Leases that have a term of 12 months or less at the commencement date are expensed on a straight-line basis over the lease term and do not result in the recognition of an asset or a liability.

Lease expense for operating leases is recognized on a straight-line basis over the lease term. Lease expense for finance leases is generally front-loaded as the finance lease ROU asset is depreciated on a straight-line basis, but interest expense on the liability is recognized utilizing the interest method that results in more expense during the early years of the lease. We have lease agreements with lease and non-lease components, primarily related to real estate, vehicle and information technology (“IT”) assets. For vehicle and real estate leases, we account for the lease and non-lease components as a single lease component. For IT leases, we allocate the payment between the lease and non-lease components based on the relative value of each component.

Goodwill

We have the option to first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value as a basis for determining whether it is necessary to perform an annual quantitative goodwill impairment test. We have elected this option for our reporting unit. In addition, the carrying value of goodwill must be tested for impairment on an interim basis in certain circumstances where impairment may be indicated.

When we are required or opt to perform the quantitative impairment test, the fair value of our reporting unit is estimated with either the market approach or the income approach using a discounted cash flow model. Our income approach method uses a discounted cash flow model in which cash flows anticipated over several periods, plus a terminal value at the end of that time horizon, are discounted to their present value using an appropriate rate of return.

The discounted cash flow model requires us to make projections of revenue, gross margin, operating expenses, working capital investment and fixed asset additions for our reporting unit over a multi-year period. Additionally, management must estimate a weighted-average cost of capital, which reflects a market rate, for our reporting unit for use as a discount rate. The discounted cash flows are compared to the carrying value of the reporting unit and, if less than the carrying value, the difference is recorded as a goodwill impairment loss. In addition, we also perform a sensitivity analysis to determine how much our forecasts can fluctuate before the fair value of a reporting unit would be lower than its carrying amount.

We perform the required procedures as of the end of our fiscal third quarter.

Changes in our projections or estimates, a deterioration of our operating results and the related cash flow effect or a significant increase in the discount rate could decrease the estimated fair value of our reporting unit and result in a future impairment of goodwill.

Warranty

We estimate and record a liability for standard warranty programs at the time our products are sold. Our estimates are based on historical experience and reflect management’s best estimates of expected costs at the time products are sold and subsequent adjustment to those expected costs when actual costs differ. As a result of the uncertainty surrounding the nature and frequency of product campaigns, the liability for such campaigns is recorded when we commit to a recall action or when a recall becomes probable and estimable, which generally occurs when it is announced. We review and assess the liability for these programs on a quarterly basis.

Research, Development and Engineering

Our research, development and engineering programs are focused on product improvements, product extensions, innovations and cost reductions for our customers. Research, development and engineering expenditures include salaries, contractor fees, building costs, utilities, testing, technical IT, administrative

expenses and allocation of corporate costs and are expensed, net of contract reimbursements, when incurred.

Segment Information

We operate our business as one operating segment and also one reportable segment based on the manner in which we review and evaluate operating performance. The types of products from which revenue is derived are the same as those described in the description of the business section and the accounting policies are the same as those described in the summary of significant accounting policies.

The operating results are regularly reviewed by Atmus’ chief operating decision maker on a consolidated basis. The chief operating decision maker is our Chief Executive Officer. The chief operating decision maker assesses performance for our business and decides how to allocate resources based on net income that also is reported on the income statement as consolidated net income and is regularly provided with consolidated expense information from the income statement. The measurement of business assets is reported on the balance sheet as total consolidated assets.

The chief operating decision maker uses net income predominately in the annual budget and forecasting process. The chief operating decision maker considers budget-to-actual in deciding whether to reinvest profit into the operating segment or for other entity initiatives, such as acquisitions, paying dividends, or share repurchases. The chief operating decision maker also uses the profit or loss measure for determining compensation of certain employees.

Stock-Based Compensation

We maintain a share-based compensation plan, which authorizes the granting of various equity-based incentives, including restricted stock units (“RSU”s) and performance share units (“PSU”s). Stock compensation expense is generally amortized on a straight line basis over the service period during which awards are expected to vest, generally three years.

RSUs are typically granted to selected employees on an annual basis and vest over three years. Dividend equivalents are paid during the vesting period. The fair value of our RSUs and other stock-based awards is measured at the market price of our Common Stock on the grant date.

PSUs vest based on varying performance, market and service conditions. The fair value of our PSUs is measured at the market price of our Common Stock on the grant date. The final award may equal 0-200 percent of the target grant, based on our actual performance during the vesting period.

Forfeitures are estimated on the grant date for all of our stock-based compensation awards.

Pension and other Postretirement Benefits

Pensions and other Postretirement Benefits

Atmus provides a range of benefits, including pensions, postretirement and post-employment benefits to eligible current and former employees, of which certain of our employees participate. For purposes of Atmus’ Consolidated Financial Statements, participation in Atmus plans are treated as single-employer plans. See Note 13, Pensions and Other Postretirement Benefits, for more information.

Recent Accounting Pronouncements

Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which requires a public entity to disclose significant segment expenses and other segment items on an annual and interim basis and provide in interim periods all disclosures about a reportable segment’s profit or loss and assets that are currently required annually. Additionally, it requires a public entity to disclose the title and position of the Chief Operating Decision Maker (“CODM”). The ASU does not change how a public entity identifies its operating segments, aggregates them, or applies the quantitative thresholds to determine its reportable segments. The new standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. A public entity should apply the amendments in this ASU retrospectively to all prior periods presented in the financial statements. We adopted this standard in the fourth quarter of 2024 and it did not have a material impact on our disclosures and no impacts to our results of operations, cash flows and financial condition.

Income Taxes (Topic 740): Improvements to Income Tax Disclosures

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, that requires entities to disclose additional information about federal, state, and foreign income taxes primarily related to the income tax rate reconciliation and income taxes paid. The new standard also eliminates certain existing disclosure requirements related to uncertain tax positions and unrecognized deferred tax liabilities. The guidance is effective for our fiscal year ending December 31, 2025, with early adoption permitted. The guidance does not affect recognition or measurement in our consolidated financial statements. We expect this ASU to only impact our disclosures with no impacts to our results of operations, cash flows and financial condition.

Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement

Expenses, which requires disclosure of certain costs and expenses on an interim and annual basis in the notes to the consolidated financial statements. The guidance is effective for annual reporting periods beginning after December 15, 2026 and interim periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The guidance is to be applied either prospectively to financial statements issued for reporting periods after the effective date or retrospectively to any or all prior periods presented in the financial statements. We are currently evaluating the potential impact of adopting this new guidance on our consolidated financial statements and related disclosures.