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.

§ 301.6221-1 Tax treatment determined at partnership level. ( a ) *In general.* A partner's treatment of partnership items on the partner's return may not be changed except as provided in sections 6222 through 6231 and the regulations thereunder. Thus, for example, if a partner treats an item on the partner's return consistently with the treatment of the item on the partnership return, the IRS generally cannot adjust the treatment of that item on the partner's return except through a partnership-level proceeding. Similarly, the taxpayer may not put partnership items in issue in a proceeding relating to nonpartnership items. For example, the taxpayer may not offset a potential increase in taxable income based on changes to nonpartnership items by a potential decrease based on partnership items.
( b ) *Restrictions inapplicable after items become nonpartnership items.* Section 6221 and paragraph (a) of this section cease to apply to items arising from a partnership with respect to a partner when those items cease to be partnership items with respect to that partner under section 6231(b).
( c ) *Penalties determined at partnership level.* Any penalty, addition to tax, or additional amount that relates to an adjustment to a partnership item shall be determined at the partnership level. Partner-level defenses to such items can only be asserted through refund actions following assessment and payment. Assessment of any penalty, addition to tax, or additional amount that relates to an adjustment to a partnership item shall be made based on partnership-level determinations. Partnership-level determinations include all the legal and factual determinations that underlie the determination of any penalty, addition to tax, or additional amount, other than partner-level defenses specified in paragraph (d) of this section.
( d ) *Partner-level defenses.* Partner-level defenses to any penalty, addition to tax, or additional amount that relates to an adjustment to a partnership item may not be asserted in the partnership-level proceeding, but may be asserted through separate refund actions following assessment and payment. See section 6230(c)(4). Partner-level defenses are limited to those that are personal to the partner or are dependent upon the partner's separate return and cannot be determined at the partnership level. Examples of these determinations are whether any applicable threshold underpayment of tax has been met with respect to the partner or whether the partner has met the criteria of section 6664(b) (penalties applicable only where return is filed), or section 6664(c)(1) (reasonable cause exception) subject to partnership-level determinations as to the applicability of section 6664(c)(2).
( e ) *Cross-references.* See §§ 301.6231(c)-1 and 301.6231(c)-2 for special rules relating to certain applications and claims for refund based on losses, deductions, or credits from abusive tax shelter partnerships.
( 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 § 301.6221-1T contained in 26 CFR part 1, revised April 1, 2001.
[T.D. 8965, 66 FR 50544, Oct. 4, 2001]