Rev. Proc. 2025-32: the 2026 head-of-household standard deduction is published as $24,150; the statutory rounding rule gives $24,175

Section 63(c)(7)(B)(ii) increases the $23,625 base by the cost-of-living adjustment and rounds the increase down to the next lowest multiple of $50. With the C-CPI-U values published on 11 September 2025 the increase is $559.56, rounded to $550, giving $24,175. Rev. Proc. 2025-32, section 4.14(1), publishes $24,150: its increase of $525 is not a multiple of $50 and matches rounding the whole amount instead of the increase.

Consequence

The 2026 standard deduction of a head-of-household filer is $25 lower than the amount the statute gives. This is a difference in the deduction, not in tax: the tax effect depends on the filer's bracket.

Proposed correction

$24,175, or a published statement of the authority for rounding the whole amount.

Jurisdiction

United States — federal

Act

Rev. Proc. 2025-32 (inflation-adjusted amounts for 2026)

Place

Rev. Proc. 2025-32, section 4.14(1)

Record

Discrepancy

Class

Derived figures

Where it arose

A published derived figure

Arxo's conclusion

Confirmed

Official text

Unchanged at last check

Last checked

2026-10-26

Evidence

Built by computation from the text. Quotations are verbatim from the official material; translations are ours and marked.

If any increase under this clause is not a multiple of $50, such increase shall be rounded to the next lowest multiple of $50.

by striking “ $18,000 ” both places it appears in subparagraphs (A)(i) and (B)(ii) and inserting “ $23,625 ”

$24,150

Built from the text

24175

Published

24150

How to check it without Arxo's tools

1. Open 26 U.S.C. §63, United States Code, 2024 edition (govinfo) and find 26 U.S.C. §63(c)(7)(B)(ii), last sentence. Compare the text with the quotation above. A copy is kept in this register: 1f095b810947b437-USCODE-2024-title26-subtitleA-chap1-subchapB-partI-sec63.htm (SHA-256 1f095b810947b437cbac8e1e2b2321a8257697a377645a837f036d69eb1e470d, copy of the official file).
2. Open Public Law 119-21, 139 Stat. 72 (govinfo USLM) and find P.L. 119-21 §70102(b)(1). Compare the text with the quotation above. A copy is kept in this register: 762ae9af06640f02-PLAW-119publ21.xml (SHA-256 762ae9af06640f023ddb9eb6f474ff7cfa275691de338d4fd985cfb04a7b6dea, copy of the official file).
3. Open IRS, Rev. Proc. 2025-32 (as revised 17 October 2025) and find Rev. Proc. 2025-32, section 4.14(1), Heads of Households. Compare the text with the quotation above. A copy is kept in this register: 0429fc711f7b2233-en.txt (SHA-256 0429fc711f7b22336a7cfe8b2a3e0c5af2e467eed346c0ceb181c8236cacff73, text extracted from the official source, as used to check the quotation).
4. Rebuild the value from the provisions quoted above: the text gives 24175; the publication shows 24150.
5. The finding holds if the quoted passages read as shown and the comparison gives the result stated at the top of this page. If it does not, write to us with the record ID.

How this finding was made

AI agents read the official texts, turned the provisions concerned into executable rules and ran the comparison; they also drafted this record. A person at Arxo checked the finding and approved the report before it was sent (2026-10-21).

Responsible institutions

• Internal Revenue Service, Office of Chief Counsel — author of Rev. Proc. 2025-32
• Internal Revenue Service, Tax Forms and Publications — Instructions for Form 1040 (standard deduction)

Reported to

Responses

Documents and reproduction

• Earlier publication, 2026-10-21: arxohq/arxo-irs-inflation-adjustments, FINDINGS
• Reproduction: Public evidence repository: recomputation of Rev. Proc. 2025-32 amounts — commit 4983918

History

1. 2026-10-21Confirmed by Arxo
2. 2026-10-21Published: arxohq/arxo-irs-inflation-adjustments, FINDINGS
3. 2026-10-21Receipt confirmed: Taxpayer Advocate Service (Systemic Advocacy Management System)
4. 2026-10-21Receipt confirmed: Treasury Inspector General for Tax Administration
5. 2026-10-21Reported to U.S. Government Accountability Office (e-mail)
6. 2026-10-21Reported to Taxpayer Advocate Service (Systemic Advocacy Management System) (web form)
7. 2026-10-21Reported to Treasury Inspector General for Tax Administration (web form)
8. 2026-10-26Entered in the register
9. 2026-10-26Reported to Internal Revenue Service, Office of Chief Counsel (e-mail)
10. 2026-10-26Reported to Internal Revenue Service, Tax Forms and Publications (web form)

Cite this record

Arxo Law, Arxo Findings Register, ARXO-2026-0025, https://arxo.io/findings/ARXO-2026-0025/ (status as of 2026-10-26). Data: ARXO-2026-0025.json.