Nature of Operations and Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation In the opinion of management, the accompanying consolidated financial statements contain all normal, recurring adjustments necessary to fairly present the financial position of CSX and its subsidiaries at December 31, 2024 and December 31, 2023, and the consolidated statements of income, comprehensive income, cash flows and changes in shareholders’ equity for the years ended 2024, 2023 and 2022. In addition, management has evaluated and disclosed all material events occurring subsequent to the date of the financial statements up to the date this annual report is filed on Form 10-K.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires that management make estimates in reporting the amounts of certain assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of certain revenues and expenses during the reporting period. Actual results may differ from those estimates. Critical accounting estimates using management judgment are made for the following areas: •personal injury and environmental reserves (see Note 5, Casualty, Environmental and Other Reserves); •pension plan accounting (see Note 9, Employee Benefit Plans); and •depreciation policies for assets under the group-life method (see Note 6, Properties)
Fiscal Year	Fiscal Year The Company's fiscal periods are based upon the calendar year. Except as otherwise specified, references to full years indicate CSX’s fiscal years ended on December 31, 2024, December 31, 2023, and December 31, 2022.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include results of operations of CSX and subsidiaries over which CSX has majority ownership or financial control. All significant intercompany accounts and transactions have been eliminated. Most investments in companies that were not majority-owned were carried at cost (if less than 20% owned and the Company has no significant influence) or were accounted for under the equity method (if the Company has significant influence but does not have control). These investments are reported within Investment in Affiliates and Other Companies on the consolidated balance sheets.
Cash and Cash Equivalents	Cash and Cash Equivalents On a daily basis, cash in excess of current operating requirements is invested in various highly liquid investments having a typical maturity date of three months or less at the date of acquisition. These investments are carried at cost, which approximates market value, and are classified as cash equivalents.
Investments	Investments Investments in instruments with original maturities greater than three months that will mature in less than one year are classified as short-term investments. Investments with original maturities of one year or greater are initially classified within other long-term assets, and the classification is re-evaluated at each balance sheet date.
Materials and Supplies	Materials and Supplies Materials and supplies in the consolidated balance sheets are carried at average cost and consist primarily of parts used in the repair and maintenance of track structure, equipment, and CSXT’s freight car and locomotive fleets, as well as fuel.
New Accounting Pronouncements	New Accounting Pronouncements In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2023-07, Improvements to Reportable Segment Disclosures. This standard update requires additional interim and annual disclosures about a reportable segment’s expenses, even for companies with only one reportable segment. The Company adopted this guidance for this 2024 annual report filed on Form 10-K and the standard update did not impact the Company's results of operations or financial position as the update only impacts disclosures. See Note 18, Segment Reporting and Significant Expenses. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. This standard update requires additional interim and annual disclosures about a company’s income taxes, including more detailed information around the annual rate reconciliation and income taxes paid. The Company is required to adopt the guidance for its 2025 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position. In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses. This standard update requires additional disclosures about certain expenses in commonly presented expense captions. The Company is required to adopt the guidance for its 2027 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position.
Revision of Prior Period Financial Statements	Revision of Prior Period Financial Statements During second quarter 2024, CSX completed a review of the accounting treatment for engineering scrap and certain engineering support labor and identified misstatements between the balance sheet and operating expense in previously issued financial statements. The Company determined the impacts of these misstatement were immaterial to the financial statements for all prior periods identified. For comparative purposes, the Company has made corrections to the consolidated financial statements and applicable notes for the prior periods presented in this Form 10-K. See Note 20, Revision of Prior Period Financial Statements, for additional information and quantification of prior period restatement impacts.
Earnings Per Share	Basic earnings per share is based on the weighted-average number of shares of common stock outstanding. Earnings per share, assuming dilution, is based on the weighted-average number of shares of common stock outstanding and common stock equivalents adjusted for the effects of common stock that may be issued as a result of potentially dilutive instruments. CSX's potentially dilutive instruments are made up of equity awards including employee stock options, performance and restricted stock units. When calculating diluted earnings per share, the potential shares that would be outstanding if all outstanding stock options were exercised are included. This number is different from outstanding stock options, which is included in Note 4, Stock Plans and Share-Based Compensation, because it is offset by shares CSX could repurchase using the proceeds from these hypothetical exercises to obtain the common stock equivalent.
Stock Plans and Share-Based Compensation	Under CSX's share-based compensation plans, awards consist of performance units, stock options, and restricted stock units for management and stock grants for directors. Awards granted under the various programs are determined and approved by the Compensation and Talent Management Committee of the Board of Directors. Awards to the Chief Executive Officer are approved by the full Board and awards to senior executives are approved by the Compensation and Talent Management Committee. In certain circumstances, the Chief Executive Officer or delegate approves awards to management employees other than senior executives. The Board of Directors approves awards granted to CSX's non-management directors upon recommendation of the Governance and Sustainability Committee. Share-based compensation expense for awards under share-based compensation plans and purchases made as part of the employee stock purchase plan is measured using the fair value of the award on the grant date and is recognized on a straight-line basis over the service period of the respective award. Alternatively, expense is recognized upon death or over an accelerated service period for employees whose agreements allow for continued vesting upon retirement or separation. Forfeitures are recognized as they occur.
Casualty Reserves	In accordance with the Contingencies Topic in the ASC, to the extent the value of an individual claim exceeds the self-insured retention amount, the Company would present the liability on a gross basis with a corresponding receivable for insurance recoveries. These reserves fluctuate based upon the timing of payments as well as changes in estimate. Actual results may vary from estimates due to the number, type and severity of the injury, costs of medical treatments and uncertainties in litigation. Defense and processing costs, which historically have been insignificant and are anticipated to be insignificant in the future, are not included in the recorded liabilities. Changes in casualty reserves are included in purchased services and other on the consolidated income statements. Personal Injury Personal injury reserves represent liabilities for employee work-related and third-party injuries. Work-related injuries for CSXT employees are primarily subject to the Federal Employers' Liability Act ("FELA"). CSXT retains an independent actuary to assist management in assessing the value of personal injury claims. An analysis is performed by the actuary quarterly and is reviewed by management. The methodology used by the actuary includes a development factor to reflect growth or reduction in the value of these personal injury claims based largely on CSXT's historical claims and settlement experience. These analyses did not result in a material adjustment to the personal injury reserve in 2024, 2023 or 2022. NOTE 5. Casualty, Environmental and Other Reserves, continued Occupational Occupational reserves represent liabilities arising from allegations of exposure to certain materials in the workplace (such as solvents, soaps, chemicals and diesel fumes), past exposure to asbestos or allegations of chronic physical injuries resulting from work conditions (such as repetitive stress injuries). The Company retains an independent actuary to analyze the Company’s historical claims, settlement amounts, and dismissal rates to assist in determining future anticipated claim filing rates and average settlement values. This analysis is performed by the actuary and reviewed by management quarterly. There were no material adjustments to the occupational reserve in 2024, 2023 or 2022.
Environmental Reserves	The Company is a party to various proceedings related to environmental issues, including administrative and judicial proceedings involving private parties and regulatory agencies. The Company has been identified as a potentially responsible party at approximately 230 environmentally impaired sites. Many of these are, or may be, subject to remedial action under the federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 ("CERCLA"), also known as the Superfund Law, or similar state statutes. Most of these proceedings arose from environmental conditions on properties used for ongoing or discontinued railroad operations. A number of these proceedings, however, are based on allegations that the Company, or its predecessors, sent hazardous substances to facilities owned or operated by others for treatment, recycling or disposal. In addition, some of the Company’s land holdings were leased to others for commercial or industrial uses that may have resulted in releases of hazardous substances or other regulated materials onto the property and could give rise to proceedings against the Company. Environmental reserves include liabilities assumed as a result of entities acquired by the Company, including the acquisition of Pan Am in 2022. In any such proceedings, the Company is subject to environmental clean-up and enforcement actions under the Superfund Law, as well as similar state laws that may impose joint and several liability for clean-up and enforcement costs on current and former owners and operators of a site without regard to fault or the legality of the original conduct. These costs could be substantial. NOTE 5. Casualty, Environmental and Other Reserves, continued In accordance with the Asset Retirement and Environmental Obligations Topic in the ASC, the Company reviews its role with respect to each site identified at least quarterly, giving consideration to a number of factors such as: •type of clean-up required; •nature of the Company’s alleged connection to the location (e.g., generator of waste sent to the site or owner or operator of the site); •extent of the Company’s alleged connection (e.g., volume of waste sent to the location and other relevant factors); and •number, connection and financial viability of other named and unnamed potentially responsible parties at the location. Based on management's review process, amounts have been recorded to cover contingent anticipated future environmental remediation costs with respect to each site to the extent such costs are reasonably estimable and probable. The recorded liabilities for estimated future environmental costs are undiscounted. The liability includes future costs for remediation and restoration of sites as well as any significant ongoing monitoring costs, but excludes any anticipated insurance recoveries. Payments related to these liabilities are expected to be made over the next several years. Environmental remediation costs are included in purchased services and other on the consolidated income statements. Currently, the Company does not possess sufficient information to reasonably estimate the amounts of additional liabilities, if any, on some sites until completion of future environmental studies. In addition, conditions that are currently unknown could, at any given location, result in additional exposure, the amount and materiality of which cannot presently be reasonably estimated. Based upon information currently available, however, the Company believes its environmental reserves accurately reflect the estimated cost of remedial actions currently required.
Capital Expenditures	The Company’s capital investment includes purchased and self-constructed assets and property additions that substantially extend the service life or increase the utility of those assets. Indirect costs that can be specifically traced to capital projects are also capitalized. The Company is committed to maintaining and improving its existing infrastructure and expanding its network capacity for long-term growth. Rail operations are capital intensive and CSX accounts for these costs in accordance with United States generally accepted accounting principles ("GAAP") and the Company’s capitalization policy. All properties are stated at historical cost less an allowance for accumulated depreciation. The Company’s largest category of capital investment is the replacement of track assets, which is primarily completed by CSXT employees, as well as the acquisition or construction of new assets that enable CSX to enhance its operations or provide new capacity offerings to its customers. Costs for track asset replacement and capacity projects that are capitalized include: •labor costs, because many of the assets are self-constructed; •costs to purchase or construct new track or to prepare ground for the laying of track; •welding (rail, field and plant), which are processes used to connect segments of rail; •new ballast, which is gravel and crushed stone that holds track in line; •fuels and lubricants associated with tie, rail and surfacing work, which is the process of raising track to a designated elevation over an extended distance; •cross, switch and bridge ties, which are the braces that support the rails on a track; •gauging, which is the process of standardizing the distance between rails; •handling costs associated with installing rail, ties or ballast; •usage charge of machinery and equipment utilized in construction or installation; and •other track materials. Labor is a significant cost in self-constructed track replacement work. CSXT engineering employees directly charge their labor to the track replacement project (the capitalized depreciable property). In replacing track, these employees concurrently perform deconstruction and installation of track material. Because of this concurrent process, CSX must estimate the amount of labor that is related to deconstruction versus installation. As a component of the depreciation study for road and track assets, management performs an analysis of labor costs related to the self-constructed track replacement work, which includes direct observation of track replacement processes. Through this analysis, CSX determined that approximately 20% of labor costs associated with track replacement is related to the deconstruction of old track, for which certain elements are expensed, and approximately 80% is associated with the installation of new track, which is capitalized. Capital investment related to locomotives and freight cars comprises the second largest category of the Company’s capital assets. This category includes purchases of locomotives and freight cars as well as costs to modify or rebuild these assets, which are capitalized if the investment incurred extends the asset’s service life or improves utilization. Improvement projects must meet specified dollar thresholds to be capitalized and are reviewed by management to determine proper accounting treatment. Routine repairs, overhauls and other maintenance costs, for all asset categories, are expensed as incurred. Group-Life Assets Sales and Retirements Since the rail network is one contiguous, connected network it is impractical to maintain specific identification records for these assets. For track assets (e.g., rail, ties, and ballast), CSX retires assets on a statistical curve relative to the age of the assets. Equipment assets (e.g., locomotives and freight cars) are specifically identified at retirement. When an equipment asset is retired that has been depreciated using the group-life method, the cost is reduced from the cost base and recorded in accumulated depreciation. For sales or retirements of assets depreciated under the group-life method that occur in the ordinary course of business, the asset cost (net of salvage value or sales proceeds) is charged to accumulated depreciation and no gain or loss is immediately recognized. This practice is consistent with accounting treatment prescribed under the group-life method. As part of the depreciation study, an assessment of the recorded amount of accumulated depreciation is made to determine if it is deficient (or in excess) of the appropriate amount indicated by the study. Any such deficiency (or excess), including any deferred gains or losses, is amortized as a component of depreciation expense over the remaining service life of the asset group until the next required depreciation study. Since the overall assumption with the group-life method is that the assets within the group on average have the same service life and characteristics, it is therefore concluded that the deferred gains and losses offset over time. For sales or retirements of assets depreciated under the group-life method that do not occur in the ordinary course of business, a gain or loss may be recognized if the sale or retirement meets each of the following three criteria: (i) it is unusual, (ii) it is material in amount, and (iii) it varies significantly from the retirement profile identified through depreciation studies. No material gains or losses were recognized on the sale of assets depreciated using the group-life method in 2024, 2023 or 2022, as no sales met the criteria described above. Land and Straight-line Assets Sales and Retirements When the Company sells or retires land, land-related easements or assets depreciated under the straight-line method, a gain or loss is recognized in purchased services and other on the consolidated statements of income
Depreciation Method	The depreciable assets of the Company are depreciated using either the group-life or straight-line method of accounting, which are both acceptable depreciation methods in accordance with GAAP. The Company depreciates its railroad assets, including main-line track, locomotives and freight cars, using the group-life method. Assets depreciated under the group-life method comprise 86% of total fixed assets of $52.2 billion on a gross basis as of December 2024. The remaining depreciable assets of the Company, including non-railroad assets and assets under finance leases, are depreciated using the straight-line method on a per asset basis. Land is not depreciated. The group-life method aggregates assets with similar lives and characteristics into groups and depreciates each of these groups as a whole. When using the group-life method, an underlying assumption is that each group of assets, as a whole, is used and depreciated to the end of its group’s recoverable life. The Company currently utilizes different depreciable asset categories to account for depreciation expense for the railroad assets that are depreciated under the group-life method. By utilizing various depreciable categories, the Company can more accurately account for the use of its assets. All assets of the Company are depreciated on a time or life basis. The group-life method of depreciation closely approximates the straight-line method of depreciation. Additionally, due to the nature of most of its assets (e.g. track is one contiguous, connected asset), the Company believes that this is the most accurate and effective way to properly depreciate its assets. Depreciation Studies Management performs a review of depreciation expense and useful lives on a regular basis. Under the group-life method, the service lives and salvage values for each group of assets are determined by completing periodic depreciation studies and applying management’s methods to determine the service lives of its properties. A depreciation study is the periodic review of asset service lives, salvage values, accumulated depreciation, and other related factors for group assets conducted by a third-party specialist, analyzed by the Company’s management and approved by the Surface Transportation Board ("STB"), the regulatory board that has broad jurisdiction over railroad practices. The STB requires depreciation studies be performed every three years for equipment assets (e.g., locomotives and freight cars) and every six years for road and track assets (e.g., bridges, signals, rail, ties, and ballast). The Company believes the frequency of depreciation studies currently required by the STB, complemented by annual data reviews conducted by a third-party specialist and analyzed by the Company's management, provides adequate review of asset service lives and that a more frequent review would not result in a material change due to the long-lived nature of most of the assets.
Impairment Review	Properties and other long-lived assets are reviewed for impairment whenever events or business conditions indicate the carrying amount of such assets may not be fully recoverable. Initial assessments of recoverability are based on estimates of undiscounted future net cash flows associated with an asset or a group of assets in accordance with the Property, Plant, and Equipment Topic in the ASC. Where impairment is indicated, the assets are evaluated and their carrying amount is reduced to fair value based on discounted net cash flows or other estimates of fair value.Impairment expense is recorded in purchased services and other expense on the consolidated income statement.
Leases	At inception, the Company determines if an arrangement contains a lease and whether that lease meets the classification criteria of a finance or operating lease. Some of the Company’s lease arrangements contain lease components (e.g., minimum rent payments) and non-lease components (e.g., maintenance, labor charges, etc.). The Company generally accounts for each component separately based on the estimated standalone price of each component. For certain equipment leases, such as freight car, vehicles and work equipment, the Company accounts for the lease and non-lease components as a single lease component. Certain of the Company’s lease agreements include rental payments that are adjusted periodically for an index or rate. The leases are initially measured using the projected payments adjusted for the index or rate in effect at the commencement date. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants. Operating Leases Operating leases are included in right-of-use lease assets, other current liabilities and long-term lease liabilities on the consolidated balance sheets. These assets and liabilities are recognized at the commencement date based on the present value of remaining lease payments over the lease term using the Company’s secured incremental borrowing rates or implicit rates, when readily determinable. Short-term operating leases, which have an initial term of 12 months or less, are not recorded on the balance sheet. The Company has various lease agreements with other parties with terms up to 50 years, including a significant operating lease with the State of Georgia for approximately 137 miles of right-of-way with integral track assets for a term of 50 years with an annual 2.5% increase. Non-cancelable, long-term leases may include provisions for maintenance, options to purchase and options to extend the terms. These options are included in the lease term when it is reasonably certain that the option will be exercised. Lease expense for operating leases, including leases with escalations over their terms, is recognized on a straight-line basis over the lease term. Variable lease expense is recognized in the period in which the obligation for those payments is incurred. Lease expense is included in equipment and other rents on the consolidated income statements and is reported net of lease income. Lease income was not material to the results of operations for 2024, 2023 or 2022. Finance leases are included in properties - net and long-term debt on the consolidated balance sheets and were not material as of December 2024 or December 2023. The associated amortization expense and interest expense are included in depreciation and interest expense, respectively, on the consolidated income statements
Revenue Recognition	The Company generates revenue from rail freight billings under contracts with customers generally on a rate per carload, container or ton-basis based on length of haul and commodities carried. The Company’s performance obligation arises when it receives a bill of lading (“BOL”) to transport a customer's commodities at a negotiated price contained in a transportation services agreement or a publicly disclosed tariff rate. Once a BOL is received, a contract is formed whereby the parties are committed to perform, collectability of consideration is probable and the rights of the parties, shipping terms and conditions, and payment terms are identified. A customer may submit several BOLs for transportation services at various times throughout a service agreement term, but each shipment represents a distinct service that is a separately identified performance obligation. NOTE 11. Revenues, continued The average transit time to complete a rail shipment is between 2 to 7 days depending on market. Payments for transportation services are normally billed once a BOL is received and are generally due within 15 days after the invoice date. The Company recognizes revenue over transit time of freight as it moves from origin to destination. Revenue for services started but not completed at the reporting date is allocated based on the relative transit time in each reporting period, with the portion allocated for services subsequent to the reporting date considered remaining performance obligations. The certain key estimates included in the recognition and measurement of revenue and related accounts receivable are as follows: •Revenue associated with shipments in transit, which is recognized ratably over transit time and is based on average cycle times to move commodities and products from their origin to their final destination or interchange; •Adjustments to revenue for billing corrections and billing discounts; •Adjustments to revenue for overcharge claims filed by customers, which are based on historical payments to customers for rate overcharges as a percentage of total billing; and •Incentive-based refunds to customers, which are primarily volume-related, are recorded as a reduction to revenue on the basis of the projected liability (this estimate is based on historical activity, current volume levels and forecasted future volume). Revenue related to interline transportation services that involve the services of another party, such as another railroad, is reported on a net basis. The portion of the gross amount billed to customers that is remitted by the Company to another party is not reflected as revenue. Trucking revenue includes revenue from the operations of Quality Carriers and is mostly comprised of truck shipments of chemicals. A performance obligation arises when Quality Carriers receives a customer order to transport a commodity at a contracted rate. Revenue is recorded on a gross basis ratably over transit time. Other revenue is recorded upon completion of the service and is comprised of revenue from regional subsidiary railroads and incidental charges, including demurrage, intermodal storage and equipment usage, and switching. Revenue from regional subsidiary railroads includes shipments by railroads that the Company does not directly operate. Demurrage represents charges assessed when freight cars are held by a customer beyond a specified period of time. Intermodal storage represents charges for customer storage of containers at an intermodal terminal, ramp facility or offsite location beyond a specified period of time. Switching represents charges assessed when a railroad switches cars for a customer or another railroad. During 2024, 2023 and 2022, revenue recognized from performance obligations related to prior periods was not material. NOTE 11. Revenues, continued Remaining Performance Obligations Remaining performance obligations represent the transaction price allocated to future reporting periods for freight services started but not completed at the reporting date. This includes the unearned portion of billed and unbilled amounts for cancellable freight shipments in transit. The Company expects to recognize the unearned portion of revenue for freight services in transit within one week of the reporting date. As of December 31, 2024, remaining performance obligations were not material. Contract Balances and Accounts Receivable The timing of revenue recognition, billings and cash collections results in accounts receivable and customer advances and deposits (contract liabilities) on the consolidated balance sheets.
Allowance for Credit Losses	Freight receivables include amounts earned, billed and unbilled, and currently due from customers for transportation-related services. Non-freight receivables include amounts billed and unbilled and currently due related to non-revenue receivables, including government reimbursement receivables. The Company maintains an allowance for credit losses to provide for the estimated amount of receivables that will not be collected. The allowance is based upon an assessment of risk characteristics, historical payment experience, and the age of outstanding receivables adjusted for forward-looking economic conditions as necessary.
Fair Value Measurements	The Financial Instruments Topic in the ASC requires disclosures about fair value of financial instruments in annual reports as well as in quarterly reports. For CSX, this statement applies to certain investments, pension plan assets, long-term debt and interest rate derivatives. The Fair Value Measurements and Disclosures Topic in the ASC clarifies the definition of fair value for financial reporting, establishes a framework for measuring fair value, including on a non-recurring basis, and requires additional disclosures about the use of fair value measurements. Various inputs are considered when determining the value of the Company's investments, pension plan assets, long-term debt, interest rate derivatives and long-lived assets. The inputs or methodologies used for valuing financial instruments are not necessarily an indication of the risk associated with investing in these financial instruments. These inputs are summarized in the three broad levels listed below: •Level 1 – observable market inputs that are unadjusted quoted prices for identical assets or liabilities in active markets; •Level 2 – other significant observable inputs (including quoted prices for similar securities, interest rates, credit risk, etc.); and •Level 3 – significant unobservable inputs (including the Company’s own assumptions about the assumptions market participants would use in determining the fair value of investments). The valuation methods described below may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date. Investments The Company's investment assets are carried at fair value on the consolidated balance sheet in accordance with the Fair Value Measurements and Disclosures Topic in the ASC. They are valued with assistance from a third-party trustee and consist of fixed income mutual funds, exchange-traded funds, corporate bonds, asset-backed securities, government securities, and short-term time deposits. The fixed income mutual funds are valued at the net asset value of shares held based on quoted market prices determined in an active market, which are Level 1 inputs. The exchange-traded funds are valued at quoted market prices determined in an active market, which are Level 1 inputs. The corporate bonds, asset-backed securities and government securities are valued using broker quotes that utilize observable market inputs, which are Level 2 inputs. The carrying amount of time deposits as reported in the consolidated balance sheet, using Level 2 inputs, approximate fair value due to their short-term nature. Unrealized losses as of December 31, 2024 and December 31, 2023 were not material. The Company believes any impairment of investments held with gross unrealized losses to be temporary and not the result of credit risk. Long-term Debt Long-term debt, which includes finance leases, is reported at carrying amount on the consolidated balance sheets and is the Company's only financial instrument with fair values significantly different from their carrying amounts. The majority of the Company's long-term debt is valued with assistance from a third party that utilizes closing transactions, market quotes or market values of comparable debt. For those instruments not valued by the third party, the fair value has been estimated by applying market rates of similar instruments to the scheduled contractual debt payments and maturities. These market rates are provided by the same third party. All of the inputs used to determine the fair value of the Company's long-term debt are Level 2 inputs. The fair value of outstanding debt fluctuates with changes in a number of factors. Such factors include, but are not limited to, interest rates, market conditions, credit ratings, values of similar financial instruments, size of the instrument, cash flow projections and comparable trades. Fair value will exceed carrying value when the current market interest rate is lower than the interest rate at which the debt was originally issued. The fair value of a company's debt is a measure of its current value under present market conditions. It does not impact the financial statements under current accounting rules.nterest Rate Derivatives The Company’s fixed-to-floating and forward starting interest rate swaps are carried at their respective fair values, which are determined with assistance from a third party based upon pricing models using inputs observed from actively quoted markets. All of the inputs used to determine the fair value of the swaps are Level 2 inputs. The fair value of the Company’s fixed-to-floating interest rate swaps was an asset of $7 million and $19 million (for swaps entered in 2023) and a liability of $123 million and $107 million (for swaps entered in 2022) as of December 31, 2024 and December 31, 2023, respectively. The fair value of the Company’s forward starting interest rate swaps asset was $48 million as of December 31, 2023. As of December 31, 2024, the forward interest rate swap was fully settled and there was no related asset or liability. See Note 10, Debt and Credit Agreements, for further information. NOTE 13. Fair Value Measurements, continued Pension Plan Assets Pension plan assets are reported at fair value, net of pension liabilities, on the consolidated balance sheet. See Note 9, Employee Benefit Plans, for further information. There are several valuation methodologies used for those assets as described below. Investments in the Fair Value Hierarchy •Common stock (Level 1): Valued at the closing price reported on the active market on which the individual securities are traded on the last day of the year and classified in Level 1 of the fair value hierarchy. •Mutual funds (Level 1): Valued at the net asset value of shares held at year end based on quoted market prices determined in an active market. These assets are classified in Level 1 of the fair value hierarchy. •Cash and cash equivalents (Level 1): Includes cash and short term investments with an original maturity of three months or less. The carrying value of cash and cash equivalents at year end approximates fair value. These assets are classified in Level 1 of the fair value hierarchy. •Corporate bonds, government securities, asset-backed securities and derivatives (Level 2): Valued using price evaluations reflecting the bid and/or ask sides of the market for a similar investment at year end. Asset-backed securities include commercial mortgage-backed securities and collateralized mortgage obligations. These assets are classified in Level 2 of the fair value hierarchy. Investments Measured at Net Asset Value •Partnerships: Net asset value of private equity is based on the fair market values associated with the underlying investments at year end. These funds have varying redemption restrictions, but most require advanced notice of at least 15 business days. •Commingled and common collective trust funds: This class consists of private funds that invest in corporate equity and debt securities, government securities and various short-term debt instruments and are measured at net asset value to estimate the fair value of the investments. The net asset value of the investments is determined by reference to the fair value of the underlying securities, which are valued primarily through the use of directly or indirectly observable inputs. These funds have redemption restrictions that require advanced notice of up to 45 business days

Nature of Operations and Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

In the opinion of management, the accompanying consolidated financial statements contain all normal, recurring adjustments necessary to fairly present the financial position of CSX and its subsidiaries at December 31, 2024 and December 31, 2023, and the consolidated statements of income, comprehensive income, cash flows and changes in shareholders’ equity for the years ended 2024, 2023 and 2022. In addition, management has evaluated and disclosed all material events occurring subsequent to the date of the financial statements up to the date this annual report is filed on Form 10-K.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires that management make estimates in reporting the amounts of certain assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of certain revenues and expenses during the reporting period. Actual results may differ from those estimates. Critical accounting estimates using management judgment are made for the following areas:

•personal injury and environmental reserves (see Note 5, Casualty, Environmental and Other Reserves);

•pension plan accounting (see Note 9, Employee Benefit Plans); and

•depreciation policies for assets under the group-life method (see Note 6, Properties)

Fiscal Year

The Company's fiscal periods are based upon the calendar year. Except as otherwise specified, references to full years indicate CSX’s fiscal years ended on December 31, 2024, December 31, 2023, and December 31, 2022.

Principles of Consolidation

The consolidated financial statements include results of operations of CSX and subsidiaries over which CSX has majority ownership or financial control. All significant intercompany accounts and transactions have been eliminated. Most investments in companies that were not majority-owned were carried at cost (if less than 20% owned and the Company has no significant influence) or were accounted for under the equity method (if the Company has significant influence but does not have control). These investments are reported within Investment in Affiliates and Other Companies on the consolidated balance sheets.

Cash and Cash Equivalents

On a daily basis, cash in excess of current operating requirements is invested in various highly liquid investments having a typical maturity date of three months or less at the date of acquisition. These investments are carried at cost, which approximates market value, and are classified as cash equivalents.

Investments

Investments in instruments with original maturities greater than three months that will mature in less than one year are classified as short-term investments. Investments with original maturities of one year or greater are initially classified within other long-term assets, and the classification is re-evaluated at each balance sheet date.

Materials and Supplies

Materials and supplies in the consolidated balance sheets are carried at average cost and consist primarily of parts used in the repair and maintenance of track structure, equipment, and CSXT’s freight car and locomotive fleets, as well as fuel.

New Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2023-07, Improvements to Reportable Segment Disclosures. This standard update requires additional interim and annual disclosures about a reportable segment’s expenses, even for companies with only one reportable segment. The Company adopted this guidance for this 2024 annual report filed on Form 10-K and the standard update did not impact the Company's results of operations or financial position as the update only impacts disclosures. See Note 18, Segment Reporting and Significant Expenses.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. This standard update requires additional interim and annual disclosures about a company’s income taxes, including more detailed information around the annual rate reconciliation and income taxes paid. The Company is required to adopt the guidance for its 2025 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position.

In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses. This standard update requires additional disclosures about certain expenses in commonly presented expense captions. The Company is required to adopt the guidance for its 2027 annual report filed on Form 10-K, though early adoption is permitted. The Company is currently evaluating the impact of these amendments on its disclosures, but this standard update will not impact the Company's results of operations or financial position.

Revision of Prior Period Financial Statements

During second quarter 2024, CSX completed a review of the accounting treatment for engineering scrap and certain engineering support labor and identified misstatements between the balance sheet and operating expense in previously issued financial statements. The Company determined the impacts of these misstatement were immaterial to the financial statements for all prior periods identified. For comparative purposes, the Company has made corrections to the consolidated financial statements and applicable notes for the prior periods presented in this Form 10-K. See Note 20, Revision of Prior Period Financial Statements, for additional information and quantification of prior period restatement impacts.

Earnings Per Share

Basic earnings per share is based on the weighted-average number of shares of common stock outstanding. Earnings per share, assuming dilution, is based on the weighted-average number of shares of common stock outstanding and common stock equivalents adjusted for the effects of common stock that may be issued as a result of potentially dilutive instruments. CSX's potentially dilutive instruments are made up of equity awards including employee stock options, performance and restricted stock units.

When calculating diluted earnings per share, the potential shares that would be outstanding if all outstanding stock options were exercised are included. This number is different from outstanding stock options, which is included in Note 4, Stock Plans and Share-Based Compensation, because it is offset by shares CSX could repurchase using the proceeds from these hypothetical exercises to obtain the common stock equivalent.

Stock Plans and Share-Based Compensation

Under CSX's share-based compensation plans, awards consist of performance units, stock options, and restricted stock units for management and stock grants for directors. Awards granted under the various programs are determined and approved by the Compensation and Talent Management Committee of the Board of Directors. Awards to the Chief Executive Officer are approved by the full Board and awards to senior executives are approved by the Compensation and Talent Management Committee. In certain circumstances, the Chief Executive Officer or delegate approves awards to management employees other than senior executives. The Board of Directors approves awards granted to CSX's non-management directors upon recommendation of the Governance and Sustainability Committee.

Share-based compensation expense for awards under share-based compensation plans and purchases made as part of the employee stock purchase plan is measured using the fair value of the award on the grant date and is recognized on a straight-line basis over the service period of the respective award. Alternatively, expense is recognized upon death or over an accelerated service period for employees whose agreements allow for continued vesting upon retirement or separation. Forfeitures are recognized as they occur.

Casualty Reserves

In accordance with the Contingencies Topic in the ASC, to the extent the value of an individual claim exceeds the self-insured retention amount, the Company would present the liability on a gross basis with a corresponding receivable for insurance recoveries.

These reserves fluctuate based upon the timing of payments as well as changes in estimate. Actual results may vary from estimates due to the number, type and severity of the injury, costs of medical treatments and uncertainties in litigation. Defense and processing costs, which historically have been insignificant and are anticipated to be insignificant in the future, are not included in the recorded liabilities. Changes in casualty reserves are included in purchased services and other on the consolidated income statements.

Personal Injury

Personal injury reserves represent liabilities for employee work-related and third-party injuries. Work-related injuries for CSXT employees are primarily subject to the Federal Employers' Liability Act ("FELA"). CSXT retains an independent actuary to assist management in assessing the value of personal injury claims. An analysis is performed by the actuary quarterly and is reviewed by management. The methodology used by the actuary includes a development factor to reflect growth or reduction in the value of these personal injury claims based largely on CSXT's historical claims and settlement experience. These analyses did not result in a material adjustment to the personal injury reserve in 2024, 2023 or 2022.

NOTE 5. Casualty, Environmental and Other Reserves, continued

Occupational

Occupational reserves represent liabilities arising from allegations of exposure to certain materials in the workplace (such as solvents, soaps, chemicals and diesel fumes), past exposure to asbestos or allegations of chronic physical injuries resulting from work conditions (such as repetitive stress injuries). The Company retains an independent actuary to analyze the Company’s historical claims, settlement amounts, and dismissal rates to assist in determining future anticipated claim filing rates and average settlement values. This analysis is performed by the actuary and reviewed by management quarterly. There were no material adjustments to the occupational reserve in 2024, 2023 or 2022.

Environmental Reserves

The Company is a party to various proceedings related to environmental issues, including administrative and judicial proceedings involving private parties and regulatory agencies. The Company has been identified as a potentially responsible party at approximately 230 environmentally impaired sites. Many of these are, or may be, subject to remedial action under the federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 ("CERCLA"), also known as the Superfund Law, or similar state statutes. Most of these proceedings arose from environmental conditions on properties used for ongoing or discontinued railroad operations. A number of these proceedings, however, are based on allegations that the Company, or its predecessors, sent hazardous substances to facilities owned or operated by others for treatment, recycling or disposal. In addition, some of the Company’s land holdings were leased to others for commercial or industrial uses that may have resulted in releases of hazardous substances or other regulated materials onto the property and could give rise to proceedings against the Company. Environmental reserves include liabilities assumed as a result of entities acquired by the Company, including the acquisition of Pan Am in 2022.

In any such proceedings, the Company is subject to environmental clean-up and enforcement actions under the Superfund Law, as well as similar state laws that may impose joint and several liability for clean-up and enforcement costs on current and former owners and operators of a site without regard to fault or the legality of the original conduct. These costs could be substantial.

NOTE 5. Casualty, Environmental and Other Reserves, continued

In accordance with the Asset Retirement and Environmental Obligations Topic in the ASC, the Company reviews its role with respect to each site identified at least quarterly, giving consideration to a number of factors such as:

•type of clean-up required;

•nature of the Company’s alleged connection to the location (e.g., generator of waste sent to the site or owner or operator of the site);

•extent of the Company’s alleged connection (e.g., volume of waste sent to the location and other relevant factors); and

•number, connection and financial viability of other named and unnamed potentially responsible parties at the location.

Based on management's review process, amounts have been recorded to cover contingent anticipated future environmental remediation costs with respect to each site to the extent such costs are reasonably estimable and probable. The recorded liabilities for estimated future environmental costs are undiscounted. The liability includes future costs for remediation and restoration of sites as well as any significant ongoing monitoring costs, but excludes any anticipated insurance recoveries. Payments related to these liabilities are expected to be made over the next several years. Environmental remediation costs are included in purchased services and other on the consolidated income statements.

Currently, the Company does not possess sufficient information to reasonably estimate the amounts of additional liabilities, if any, on some sites until completion of future environmental studies. In addition, conditions that are currently unknown could, at any given location, result in additional exposure, the amount and materiality of which cannot presently be reasonably estimated. Based upon information currently available, however, the Company believes its environmental reserves accurately reflect the estimated cost of remedial actions currently required.

Capital Expenditures

The Company’s capital investment includes purchased and self-constructed assets and property additions that substantially extend the service life or increase the utility of those assets. Indirect costs that can be specifically traced to capital projects are also capitalized. The Company is committed to maintaining and improving its existing infrastructure and expanding its network capacity for long-term growth. Rail operations are capital intensive and CSX accounts for these costs in accordance with United States generally accepted accounting principles ("GAAP") and the Company’s capitalization policy. All properties are stated at historical cost less an allowance for accumulated depreciation.

The Company’s largest category of capital investment is the replacement of track assets, which is primarily completed by CSXT employees, as well as the acquisition or construction of new assets that enable CSX to enhance its operations or provide new capacity offerings to its customers. Costs for track asset replacement and capacity projects that are capitalized include:

•labor costs, because many of the assets are self-constructed;

•costs to purchase or construct new track or to prepare ground for the laying of track;

•welding (rail, field and plant), which are processes used to connect segments of rail;

•new ballast, which is gravel and crushed stone that holds track in line;

•fuels and lubricants associated with tie, rail and surfacing work, which is the process of raising track to a designated elevation over an extended distance;

•cross, switch and bridge ties, which are the braces that support the rails on a track;

•gauging, which is the process of standardizing the distance between rails;

•handling costs associated with installing rail, ties or ballast;

•usage charge of machinery and equipment utilized in construction or installation; and

•other track materials.

Labor is a significant cost in self-constructed track replacement work. CSXT engineering employees directly charge their labor to the track replacement project (the capitalized depreciable property). In replacing track, these employees concurrently perform deconstruction and installation of track material. Because of this concurrent process, CSX must estimate the amount of labor that is related to deconstruction versus installation. As a component of the depreciation study for road and track assets, management performs an analysis of labor costs related to the self-constructed track replacement work, which includes direct observation of track replacement processes. Through this analysis, CSX determined that approximately 20% of labor costs associated with track replacement is related to the deconstruction of old track, for which certain elements are expensed, and approximately 80% is associated with the installation of new track, which is capitalized.

Capital investment related to locomotives and freight cars comprises the second largest category of the Company’s capital assets. This category includes purchases of locomotives and freight cars as well as costs to modify or rebuild these assets, which are capitalized if the investment incurred extends the asset’s service life or improves utilization. Improvement projects must meet specified dollar thresholds to be capitalized and are reviewed by management to determine proper accounting treatment. Routine repairs, overhauls and other maintenance costs, for all asset categories, are expensed as incurred.

Group-Life Assets Sales and Retirements

Since the rail network is one contiguous, connected network it is impractical to maintain specific identification records for these assets. For track assets (e.g., rail, ties, and ballast), CSX retires assets on a statistical curve relative to the age of the assets. Equipment assets (e.g., locomotives and freight cars) are specifically identified at retirement. When an equipment asset is retired that has been depreciated using the group-life method, the cost is reduced from the cost base and recorded in accumulated depreciation.

For sales or retirements of assets depreciated under the group-life method that occur in the ordinary course of business, the asset cost (net of salvage value or sales proceeds) is charged to accumulated depreciation and no gain or loss is immediately recognized. This practice is consistent with accounting treatment prescribed under the group-life method. As part of the depreciation study, an assessment of the recorded amount of accumulated depreciation is made to determine if it is deficient (or in excess) of the appropriate amount indicated by the study. Any such deficiency (or excess), including any deferred gains or losses, is amortized as a component of depreciation expense over the remaining service life of the asset group until the next required depreciation study. Since the overall assumption with the group-life method is that the assets within the group on average have the same service life and characteristics, it is therefore concluded that the deferred gains and losses offset over time.

For sales or retirements of assets depreciated under the group-life method that do not occur in the ordinary course of business, a gain or loss may be recognized if the sale or retirement meets each of the following three criteria: (i) it is unusual, (ii) it is material in amount, and (iii) it varies significantly from the retirement profile identified through depreciation studies. No material gains or losses were recognized on the sale of assets depreciated using the group-life method in 2024, 2023 or 2022, as no sales met the criteria described above.

Land and Straight-line Assets Sales and Retirements

When the Company sells or retires land, land-related easements or assets depreciated under the straight-line method, a gain or loss is recognized in purchased services and other on the consolidated statements of income

Depreciation Method

The depreciable assets of the Company are depreciated using either the group-life or straight-line method of accounting, which are both acceptable depreciation methods in accordance with GAAP. The Company depreciates its railroad assets, including main-line track, locomotives and freight cars, using the group-life method. Assets depreciated under the group-life method comprise 86% of total fixed assets of $52.2 billion on a gross basis as of December 2024. The remaining depreciable assets of the Company, including non-railroad assets and assets under finance leases, are depreciated using the straight-line method on a per asset basis. Land is not depreciated.

The group-life method aggregates assets with similar lives and characteristics into groups and depreciates each of these groups as a whole. When using the group-life method, an underlying assumption is that each group of assets, as a whole, is used and depreciated to the end of its group’s recoverable life. The Company currently utilizes different depreciable asset categories to account for depreciation expense for the railroad assets that are depreciated under the group-life method. By utilizing various depreciable categories, the Company can more accurately account for the use of its assets. All assets of the Company are depreciated on a time or life basis.

The group-life method of depreciation closely approximates the straight-line method of depreciation. Additionally, due to the nature of most of its assets (e.g. track is one contiguous, connected asset), the Company believes that this is the most accurate and effective way to properly depreciate its assets.

Depreciation Studies

Management performs a review of depreciation expense and useful lives on a regular basis. Under the group-life method, the service lives and salvage values for each group of assets are determined by completing periodic depreciation studies and applying management’s methods to determine the service lives of its properties. A depreciation study is the periodic review of asset service lives, salvage values, accumulated depreciation, and other related factors for group assets conducted by a third-party specialist, analyzed by the Company’s management and approved by the Surface Transportation Board ("STB"), the regulatory board that has broad jurisdiction over railroad practices. The STB requires depreciation studies be performed every three years for equipment assets (e.g., locomotives and freight cars) and every six years for road and track assets (e.g., bridges, signals, rail, ties, and ballast). The Company believes the frequency of depreciation studies currently required by the STB, complemented by annual data reviews conducted by a third-party specialist and analyzed by the Company's management, provides adequate review of asset service lives and that a more frequent review would not result in a material change due to the long-lived nature of most of the assets.

Impairment Review

Properties and other long-lived assets are reviewed for impairment whenever events or business conditions indicate the carrying amount of such assets may not be fully recoverable. Initial assessments of recoverability are based on estimates of undiscounted future net cash flows associated with an asset or a group of assets in accordance with the Property, Plant, and Equipment Topic in the ASC. Where impairment is indicated, the assets are evaluated and their carrying amount is reduced to fair value based on discounted net cash flows or other estimates of fair value.Impairment expense is recorded in purchased services and other expense on the consolidated income statement.

Leases

At inception, the Company determines if an arrangement contains a lease and whether that lease meets the classification criteria of a finance or operating lease. Some of the Company’s lease arrangements contain lease components (e.g., minimum rent payments) and non-lease components (e.g., maintenance, labor charges, etc.). The Company generally accounts for each component separately based on the estimated standalone price of each component. For certain equipment leases, such as freight car, vehicles and work equipment, the Company accounts for the lease and non-lease components as a single lease component.

Certain of the Company’s lease agreements include rental payments that are adjusted periodically for an index or rate. The leases are initially measured using the projected payments adjusted for the index or rate in effect at the commencement date. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants.

Operating Leases

Operating leases are included in right-of-use lease assets, other current liabilities and long-term lease liabilities on the consolidated balance sheets. These assets and liabilities are recognized at the commencement date based on the present value of remaining lease payments over the lease term using the Company’s secured incremental borrowing rates or implicit rates, when readily determinable. Short-term operating leases, which have an initial term of 12 months or less, are not recorded on the balance sheet.

The Company has various lease agreements with other parties with terms up to 50 years, including a significant operating lease with the State of Georgia for approximately 137 miles of right-of-way with integral track assets for a term of 50 years with an annual 2.5% increase. Non-cancelable, long-term leases may include provisions for maintenance, options to purchase and options to extend the terms. These options are included in the lease term when it is reasonably certain that the option will be exercised. Lease expense for operating leases, including leases with escalations over their terms, is recognized on a straight-line basis over the lease term. Variable lease expense is recognized in the period in which the obligation for those payments is incurred. Lease expense is included in equipment and other rents on the consolidated income statements and is reported net of lease income. Lease income was not material to the results of operations for 2024, 2023 or 2022.

Finance leases are included in properties - net and long-term debt on the consolidated balance sheets and were not material as of December 2024 or December 2023. The associated amortization expense and interest expense are included in depreciation and interest expense, respectively, on the consolidated income statements

Revenue Recognition

The Company generates revenue from rail freight billings under contracts with customers generally on a rate per carload, container or ton-basis based on length of haul and commodities carried. The Company’s performance obligation arises when it receives a bill of lading (“BOL”) to transport a customer's commodities at a negotiated price contained in a transportation services agreement or a publicly disclosed tariff rate. Once a BOL is received, a contract is formed whereby the parties are committed to perform, collectability of consideration is probable and the rights of the parties, shipping terms and conditions, and payment terms are identified. A customer may submit several BOLs for transportation services at various times throughout a service agreement term, but each shipment represents a distinct service that is a separately identified performance obligation.

NOTE 11. Revenues, continued

The average transit time to complete a rail shipment is between 2 to 7 days depending on market. Payments for transportation services are normally billed once a BOL is received and are generally due within 15 days after the invoice date. The Company recognizes revenue over transit time of freight as it moves from origin to destination. Revenue for services started but not completed at the reporting date is allocated based on the relative transit time in each reporting period, with the portion allocated for services subsequent to the reporting date considered remaining performance obligations.

The certain key estimates included in the recognition and measurement of revenue and related accounts receivable are as follows:

•Revenue associated with shipments in transit, which is recognized ratably over transit time and is based on average cycle times to move commodities and products from their origin to their final destination or interchange;

•Adjustments to revenue for billing corrections and billing discounts;

•Adjustments to revenue for overcharge claims filed by customers, which are based on historical payments to customers for rate overcharges as a percentage of total billing; and

•Incentive-based refunds to customers, which are primarily volume-related, are recorded as a reduction to revenue on the basis of the projected liability (this estimate is based on historical activity, current volume levels and forecasted future volume).

Revenue related to interline transportation services that involve the services of another party, such as another railroad, is reported on a net basis. The portion of the gross amount billed to customers that is remitted by the Company to another party is not reflected as revenue.

Trucking revenue includes revenue from the operations of Quality Carriers and is mostly comprised of truck shipments of chemicals. A performance obligation arises when Quality Carriers receives a customer order to transport a commodity at a contracted rate. Revenue is recorded on a gross basis ratably over transit time.

Other revenue is recorded upon completion of the service and is comprised of revenue from regional subsidiary railroads and incidental charges, including demurrage, intermodal storage and equipment usage, and switching. Revenue from regional subsidiary railroads includes shipments by railroads that the Company does not directly operate. Demurrage represents charges assessed when freight cars are held by a customer beyond a specified period of time. Intermodal storage represents charges for customer storage of containers at an intermodal terminal, ramp facility or offsite location beyond a specified period of time. Switching represents charges assessed when a railroad switches cars for a customer or another railroad.

During 2024, 2023 and 2022, revenue recognized from performance obligations related to prior periods was not material.

NOTE 11. Revenues, continued

Remaining Performance Obligations

Remaining performance obligations represent the transaction price allocated to future reporting periods for freight services started but not completed at the reporting date. This includes the unearned portion of billed and unbilled amounts for cancellable freight shipments in transit. The Company expects to recognize the unearned portion of revenue for freight services in transit within one week of the reporting date. As of December 31, 2024, remaining performance obligations were not material.

Contract Balances and Accounts Receivable

The timing of revenue recognition, billings and cash collections results in accounts receivable and customer advances and deposits (contract liabilities) on the consolidated balance sheets.

Allowance for Credit Losses

Freight receivables include amounts earned, billed and unbilled, and currently due from customers for transportation-related services. Non-freight receivables include amounts billed and unbilled and currently due related to non-revenue receivables, including government reimbursement receivables. The Company maintains an allowance for credit losses to provide for the estimated amount of receivables that will not be collected. The allowance is based upon an assessment of risk characteristics, historical payment experience, and the age of outstanding receivables adjusted for forward-looking economic conditions as necessary.

Fair Value Measurements

The Financial Instruments Topic in the ASC requires disclosures about fair value of financial instruments in annual reports as well as in quarterly reports. For CSX, this statement applies to certain investments, pension plan assets, long-term debt and interest rate derivatives. The Fair Value Measurements and Disclosures Topic in the ASC clarifies the definition of fair value for financial reporting, establishes a framework for measuring fair value, including on a non-recurring basis, and requires additional disclosures about the use of fair value measurements.

Various inputs are considered when determining the value of the Company's investments, pension plan assets, long-term debt, interest rate derivatives and long-lived assets. The inputs or methodologies used for valuing financial instruments are not necessarily an indication of the risk associated with investing in these financial instruments. These inputs are summarized in the three broad levels listed below:

•Level 1 – observable market inputs that are unadjusted quoted prices for identical assets or liabilities in active markets;

•Level 2 – other significant observable inputs (including quoted prices for similar securities, interest rates, credit risk, etc.); and

•Level 3 – significant unobservable inputs (including the Company’s own assumptions about the assumptions market participants would use in determining the fair value of investments).

The valuation methods described below may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, while the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

Investments

The Company's investment assets are carried at fair value on the consolidated balance sheet in accordance with the Fair Value Measurements and Disclosures Topic in the ASC. They are valued with assistance from a third-party trustee and consist of fixed income mutual funds, exchange-traded funds, corporate bonds, asset-backed securities, government securities, and short-term time deposits. The fixed income mutual funds are valued at the net asset value of shares held based on quoted market prices determined in an active market, which are Level 1 inputs. The exchange-traded funds are valued at quoted market prices determined in an active market, which are Level 1 inputs. The corporate bonds, asset-backed securities and government securities are valued using broker quotes that utilize observable market inputs, which are Level 2 inputs. The carrying amount of time deposits as reported in the consolidated balance sheet, using Level 2 inputs, approximate fair value due to their short-term nature. Unrealized losses as of December 31, 2024 and December 31, 2023 were not material. The Company believes any impairment of investments held with gross unrealized losses to be temporary and not the result of credit risk.

Long-term Debt

Long-term debt, which includes finance leases, is reported at carrying amount on the consolidated balance sheets and is the Company's only financial instrument with fair values significantly different from their carrying amounts. The majority of the Company's long-term debt is valued with assistance from a third party that utilizes closing transactions, market quotes or market values of comparable debt. For those instruments not valued by the third party, the fair value has been estimated by applying market rates of similar instruments to the scheduled contractual debt payments and maturities. These market rates are provided by the same third party. All of the inputs used to determine the fair value of the Company's long-term debt are Level 2 inputs.

The fair value of outstanding debt fluctuates with changes in a number of factors. Such factors include, but are not limited to, interest rates, market conditions, credit ratings, values of similar financial instruments, size of the instrument, cash flow projections and comparable trades. Fair value will exceed carrying value when the current market interest rate is lower than the interest rate at which the debt was originally issued. The fair value of a company's debt is a measure of its current value under present market conditions. It does not impact the financial statements under current accounting rules.nterest Rate Derivatives

The Company’s fixed-to-floating and forward starting interest rate swaps are carried at their respective fair values, which are determined with assistance from a third party based upon pricing models using inputs observed from actively quoted markets. All of the inputs used to determine the fair value of the swaps are Level 2 inputs. The fair value of the Company’s fixed-to-floating interest rate swaps was an asset of $7 million and $19 million (for swaps entered in 2023) and a liability of $123 million and $107 million (for swaps entered in 2022) as of December 31, 2024 and December 31, 2023, respectively. The fair value of the Company’s forward starting interest rate swaps asset was $48 million as of December 31, 2023. As of December 31, 2024, the forward interest rate swap was fully settled and there was no related asset or liability. See Note 10, Debt and Credit Agreements, for further information.

NOTE 13. Fair Value Measurements, continued

Pension Plan Assets

Pension plan assets are reported at fair value, net of pension liabilities, on the consolidated balance sheet. See Note 9, Employee Benefit Plans, for further information. There are several valuation methodologies used for those assets as described below.

Investments in the Fair Value Hierarchy

•Common stock (Level 1): Valued at the closing price reported on the active market on which the individual securities are traded on the last day of the year and classified in Level 1 of the fair value hierarchy.

•Mutual funds (Level 1): Valued at the net asset value of shares held at year end based on quoted market prices determined in an active market. These assets are classified in Level 1 of the fair value hierarchy.

•Cash and cash equivalents (Level 1): Includes cash and short term investments with an original maturity of three months or less. The carrying value of cash and cash equivalents at year end approximates fair value. These assets are classified in Level 1 of the fair value hierarchy.

•Corporate bonds, government securities, asset-backed securities and derivatives (Level 2): Valued using price evaluations reflecting the bid and/or ask sides of the market for a similar investment at year end. Asset-backed securities include commercial mortgage-backed securities and collateralized mortgage obligations. These assets are classified in Level 2 of the fair value hierarchy.

Investments Measured at Net Asset Value

•Partnerships: Net asset value of private equity is based on the fair market values associated with the underlying investments at year end. These funds have varying redemption restrictions, but most require advanced notice of at least 15 business days.

•Commingled and common collective trust funds: This class consists of private funds that invest in corporate equity and debt securities, government securities and various short-term debt instruments and are measured at net asset value to estimate the fair value of the investments. The net asset value of the investments is determined by reference to the fair value of the underlying securities, which are valued primarily through the use of directly or indirectly observable inputs. These funds have redemption restrictions that require advanced notice of up to 45 business days