Editorial Note on Part 301
Editorial Note: In the text of this part, integral section references are to sections of the Internal Revenue Code of 1954; decimal section references are to the Code of Federal Regulations. References in the text to the “Code” are references to sections of the Internal Revenue Code of 1954.

§ 301.6231(a)(5)-1 Definition of affected item. ( a ) *In general.* The term *affected item* means any item to the extent such item is affected by a partnership item. It includes items unrelated to the items reflected on the partnership return (for example, an item, such as the threshold for the medical expense deduction under section 213, that varies if there is a change in an individual partner's adjusted gross income).
( b ) *Basis in a partner's partnership interest.* The basis of a partner's partnership interest is an affected item to the extent it is not a partnership item.
( c ) *At-risk limitation.* The application of the at-risk limitation under section 465 to a partner with respect to a loss incurred by a partnership is an affected item to the extent it is not a partnership item.
( d ) *Passive losses.* The application of the passive loss rules under section 469 to a partner with respect to a loss incurred by a partnership is an affected item to the extent it is not a partnership item.
( e ) *Penalty, addition to tax, or additional amount* — ( 1 ) *In general.* The term *affected item* includes any penalty, addition to tax, or additional amount provided by subchapter A of chapter 68 of the Internal Revenue Code of 1986 to the extent provided in this paragraph (e).
( 2 ) *Penalty, addition to tax, or additional amount without floor.* If a penalty, addition to tax, or additional amount that does not contain a floor (that is, a threshold amount of underpayment or understatement necessary before the imposition of the penalty, addition to tax, or additional amount) is imposed on a partner as the result of an adjustment to a partnership item, the term *affected item* shall include the penalty, addition to tax, or additional amount computed with reference to the portion of the underpayment that is attributable to the partnership item adjustment(s) to which the penalty, addition to tax, or additional amount applies.
( 3 ) *Penalty, addition to tax, or additional amount containing floor* — ( i ) *Floor exceeded prior to adjustment.* If a partner would have been subject to a penalty, addition to tax, or additional amount that contains a floor in the absence of an adjustment to a partnership item (that is, the partner's understatement or underpayment exceeded the floor even without an adjustment to a partnership item) the term *affected item* shall include only the portion of the penalty, addition to tax, or additional amount computed with reference to the partnership item (or affected item) adjustments.
( ii ) *Floor not exceeded prior to adjustment.* In the case of a penalty, addition to tax, or additional amount that contains a floor, if the taxpayer's understatement or underpayment does not exceed the floor prior to an adjustment to a partnership item but does so after such adjustment, the term *affected item* shall include the penalty, addition to tax, or additional amount computed with reference to the entire underpayment or understatement to which the penalty, addition to tax, or additional amount applies.
( 4 ) *Examples.* The provisions of this paragraph (e) may be illustrated by the following examples: Example 1. 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.
Example 2. 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.
Example 3. 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.
( f ) *Effective date.* This section is applicable to partnership taxable years beginning on or after October 4, 2001. For years beginning prior to October 4, 2001, see § 301.6231(a)(5)-1T contained in 26 CFR part 1, revised April 1, 2001.
[T.D. 8965, 66 FR 50557, Oct. 4, 2001]