Treasury Regulations · 26 CFR
§ 301.6231(a)(5)-1. Definition of affected item.
Regulation text, no changes From the eCFR, current as of October 15, 2026. The eCFR is an authoritative but unofficial editorial compilation of the Code of Federal Regulations; the official text is the annual CFR on govinfo. Compare it with this section on ecfr.gov (external site) or the official annual CFR on govinfo (external site).
Regulation under 26 U.S.C. § 6231(a)(5)
Cite as 26 CFR § 301.6231(a)(5)-1
At a glance
Read from the text and its source citation. Not part of the regulation.
- Status
- In the current eCFR
- Issued
- October 4, 2001 by T.D. 8965
- Issued under
- 26 U.S.C. § 6231(a)(5)
- Length
- 837 words · about 4 min to read
- Defines
- 5 terms
- Cross-references
- cites 4 Code sections and 0 regulations; cited by 0
A, a partner of P, had an aggregate underpayment of $1,000 of which $100 is attributable to an adjustment to partnership items. A is negligent in reporting the partnership items. The accuracy-related penalty under section 6662 for negligence computed with reference to the $100 underpayment attributable to the partnership item adjustments is an affected item.
B, a partner of P, understated B's income tax liability attributable to nonpartnership items by $6,000. An adjustment to a partnership item resulting from a partnership proceeding increased B's income tax by an additional $2,000. Prior to the adjustment, B would have been subject to the accuracy-related penalty under section 6662 for a substantial understatement of income tax with respect to the $6,000 understatement attributable to nonpartnership items. The portion of the accuracy-related penalty under section 6662 computed with reference to the $2,000 understatement attributable to partnership items to which the accuracy-related penalty applies is an affected item. The portion of the accuracy-related penalty under section 6662 computed with reference to the $6,000 pre-existing understatement is not an affected item.
C, a partner in partnership P, understated C's income tax liability attributable to nonpartnership items by $4,000. As a result of an adjustment to partnership items, that understatement is increased to $10,000. Prior to the adjustment, C would not have been subject to the accuracy-related penalty under section 6662 for a substantial understatement of income tax. The accuracy-related penalty under section 6662 computed with reference to the entire $10,000 understatement to which the accuracy-related penalty applies is an affected item.
[T.D. 8965, 66 FR 50557, Oct. 4, 2001]
Terms defined here
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Cross-references
Computed from the citations in the text of 26 CFR.
Code sections it cites
Amendment history
From the source citation at the end of the section, newest first. T.D. is a Treasury decision; FR is the Federal Register.
- Issued by T.D. 8965 (66 FR 50557)
Where it sits in 26 CFR
- Subchapter F Procedure and administration
- Part 301 Procedure and administration
- Subpart ECFR01918753cdbe68b Assessment
- In General
Nearby sections
- § 301.6231-1 Notice of proceedings and adjustments.
- § 301.6231(a)(1)-1 Exception for small partnerships.
- § 301.6231(a)(2)-1 Persons whose tax liability is determined indirectly by partnership items.
- § 301.6231(a)(3)-1 Partnership items.
- § 301.6231(a)(5)-1 Definition of affected item.
- § 301.6231(a)(6)-1 Computational adjustments.
- § 301.6231(a)(7)-1 Designation or selection of tax matters partner.
- § 301.6231(a)(7)-2 Designation or selection of tax matters partner for a limited liability company (LLC).
- § 301.6231(a)(12)-1 Special rules relating to spouses.