In this release, the IRS announces new 2025–2026 per diem rates, expanded excise taxes on 39 chemicals, drought-related livestock relief, and updated federal and fringe benefit valuation rates.
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The Internal Revenue Bulletin (IRB) is the authoritative instrument for announcing official rulings and procedures of the IRS and for publishing Treasury Decisions, Executive Orders, Tax Conventions, legislation, court decisions, and other items of general interest.
ADMINISTRATIVE, INCOME TAX
Notice 2025-54, page 479.
Optional special per diem rates. This notice provides the 2025-2026 special per diem rates for taxpayers to use in substantiating the amount of ordinary and necessary business expenses incurred while traveling away from home. The notice includes (1) the special transportation industry rate, (2) the rate for the incidental expenses only deduction, and (3) the rates and list of high-cost localities for the high-low substantiation method.
EXCISE TAX
Notice 2025-51, page 448.
This Notice of Determinations adds 39 chemical substances to the list of taxable substances under § 4672 subject to the tax imposed by § 4671.
INCOME TAX
Notice 2025-52, page 474.
This notice explains the circumstances under which the four-year replacement period under section 1033(e)(2) is extended for livestock sold on account of drought. The Appendix to this notice contains a list of counties that experienced exceptional, extreme, or severe drought conditions during the 12-month period ending August 31, 2025. Taxpayers may use this list to determine if any extension is available.
Rev. Rul. 2025-19, page 445.
Federal rates; adjusted federal rates; adjusted federal long-term rate, and the long-term tax-exempt rate. For purposes of sections 382, 1274, 1288, 7872 and other sections of the Code, tables set forth the rates for October 2025.
Rev. Rul. 2025-20, page 447.
Fringe benefits aircraft valuation formula. For purposes of section 1.61-21(g) of the Income Tax Regulations, relating to the rule for valuing non-commercial flights on employer-provided aircraft, the Standard Industry Fare Level (SIFL) cents-per-mile rates and terminal charge in effect for the second half of 2025 are set forth.