The "End Oil and Gas Tax Subsidies Act of 2025" proposes significant amendments to the Internal Revenue Code, primarily by eliminating various tax subsidies and benefits currently available to the oil and gas industry. Its core purpose is to repeal tax provisions that are considered favorable to fossil fuel companies, with most changes taking effect for taxable years beginning after December 31, 2024. One major aspect of the bill involves the repeal of several key tax credits and deductions. Specifically, it eliminates the credit for producing oil and gas from marginal wells and the enhanced oil recovery credit . The legislation also ends the immediate deduction for intangible drilling and development costs and repeals percentage depletion for oil and gas wells , requiring these costs to be amortized or capitalized instead. Furthermore, the bill targets other specific tax advantages, such as repealing the deduction for tertiary injectants . It also terminates the exception to passive loss limitations for working interests in oil and gas properties and prevents oil and gas activities from qualifying for the deduction for qualified business income under Section 199A. For larger entities, the legislation prohibits major integrated oil companies from using the Last-In, First-Out (LIFO) accounting method for inventory, defining these companies based on specific production, gross receipts, and refinery run thresholds. Additionally, it modifies foreign tax credit rules for "dual capacity taxpayers" to limit credits for combined foreign oil and gas income when a specific economic benefit is received from a foreign country. Finally, the bill clarifies the definition of "crude oil" for excise tax purposes to explicitly include tar sands , bitumen, and oil derived from kerogen-bearing sources. It also grants the Secretary of the Treasury regulatory authority to include other fuel feedstocks or finished fuel products if they pose a significant hazard risk and are consistent with the Oil Pollution Act of 1990.