IRS Publications and Forms Index

How to read an IRS publication in this library

Read the cover date first. Publication 5653 is revised February 2025 (cover date February 6, 2025; the IRS Audit Techniques Guides index lists publication date 02/2025). Publication 946 used here is the 2025 edition for use in preparing 2025 returns (catalog 13081F; the research register records a March 13, 2026 date on the opened PDF). Publication 527 used here is the 2025 residential-rental publication. Those dates are why a bonus-depreciation sentence that appears inside the February 2025 Audit Techniques Guide cannot be the last word after Public Law 119-21 was enacted on July 4, 2025.

Read the disclaimer that comes with the document type. Audit Techniques Guides, including Publication 5653, state that they are not official pronouncements of the law or the position of the Service and cannot be used, cited, or relied upon as such. Form instructions are filing aids. Revenue procedures and notices are official IRS guidance, but they remain administrative. Only the Code, the regulations, and court opinions sit in Tier 1.

Use a publication to learn the vocabulary the Service uses, then go back to the statute for the operative rule. Publication 946 is the place this library goes for MACRS tables, conventions, and Appendix B class lives reproduced from Rev. Proc. 87-56. Publication 527 is the place this library goes for dwelling-unit and residential-rental explanations that sit next to §168(e)(2). Publication 5653 is the place this library goes for what examiners are told to look for in a study, not for what a court must do.

Publications

Publication 5653, Cost Segregation Audit Techniques Guide, revised February 2025 — what examiners look for, including Chapter 7 industry matrices. The PDF states it is not an official pronouncement and cannot be cited as authority. Chapter 3 describes six study approaches, from detailed engineering off actual cost records to a rule-of-thumb percentage. Chapter 4 lists thirteen principal elements of a quality study and nine elements of a quality report. Chapter 6 includes case-law tables and a depreciation overview. Chapter 7 contains the only seven industry matrices in the guide. Chapter 8 discusses electrical distribution and stand-alone open-air parking structures. The guide also states that the Service has not established required preparer qualifications or a required study format.

Publication 946, How To Depreciate Property (2025) — MACRS, bonus depreciation, §179, conventions, and Appendix B class lives from Rev. Proc. 87-56. This is the handbook a return preparer actually opens for tables. The 2025 edition this library opened already describes 100 percent additional first-year depreciation for qualified property acquired after January 19, 2025, and the prior phase-down for earlier acquisitions. Appendix B is how this library cites class 00.3 land improvements, class 00.11 office furniture, class 57.0 distributive trades and services, and the statutory 27.5- and 39-year real-property classes, because the 1987 Cumulative Bulletin text of Rev. Proc. 87-56 was not found as a standalone IRS PDF.

Publication 527, Residential Rental Property (2025) — dwelling-unit and residential-rental rules that decide 27.5 versus 39 years. A building is residential rental property only if at least 80 percent of its gross rental income is from dwelling units. A dwelling unit is a house or apartment used to provide living accommodations, but not a unit in a hotel, motel, or other establishment more than one-half of whose units are used on a transient basis. Those statutory tests, explained in Publication 527, are why a short-term rental, a hotel, or a mixed-use building cannot be labeled 27.5-year property by building type alone.

Notices, procedures, and forms

Notice 2026-11 — interim guidance on additional first-year depreciation after Public Law 119-21. The notice announces forthcoming proposed regulations, applies Treas. Reg. §1.168(k)-2 with substituted dates, and states that taxpayers may rely on sections 3 through 5 only if they follow those sections in their entirety for all eligible property. It is the document this library uses for the January 19, 2025 acquisition cutoff, the written-binding-contract rule, the self-constructed 10-percent safe harbor, and the §168(k)(10) transition election of 40 percent (60 percent for certain longer-production-period property and aircraft).

Notice 2026-16 — interim guidance on qualified production property under §168(n). The notice describes an elective 100 percent allowance for a designated portion of nonresidential real property used as an integral part of a qualified production activity, with construction-begin and placed-in-service windows, and with exclusions for offices, administrative space, lodging, parking, sales, research, software development, and engineering. It is not bonus depreciation under §168(k), and it is not a cost-segregation class.

Rev. Proc. 2025-32 — 2026 inflation adjustments, including §179 dollar amounts of $2,560,000 and a phase-out threshold of $4,090,000, plus a $32,000 sport-utility-vehicle cap. Rev. Proc. 2025-23 — 2026 list of automatic accounting-method changes, later modified by Rev. Proc. 2026-32. Designated change number 7 is the usual impermissible-to-permissible depreciation change. Rev. Proc. 2015-13 remains the general procedure for method changes. Rev. Proc. 2020-25 is the qualified-improvement-property procedure this library cites for the CARES Act correction, not as a current bonus-rate table.

Instructions for Form 4562 (2025) and Instructions for Form 3115 (Rev. December 2022). Form 4562 is the depreciation and amortization form; its instructions are the place the Service tells taxpayers how to elect out of bonus depreciation by class or how to claim §179. Form 3115 is the application for change in accounting method. The December 2022 instructions still point to Rev. Proc. 2015-13 or any successor. They predate Rev. Proc. 2025-23, so change numbers in this library come from the 2025 list, not from the instruction PDF’s older examples.

Limits of this index

This is not a complete IRS forms catalog. Forms that were not opened for a CostSeg SI claim do not appear here. Revenue rulings that appear only as citations inside Publication 5653 are marked PARTIAL on the research register and are not promoted to independent holdings on this page.

Do not cite a publication as if it were §168. Do not cite the Audit Techniques Guide after July 4, 2025, as proof of the current bonus-depreciation rate. Do not treat a Super Intelligence label on a workflow screen as an IRS filing position. These documents were opened as PDFs or HTML pages on irs.gov. That is the method. It is not expert review.