26 U.S.C. § 6235: Period of limitations on making adjustments

the date on which the partnership return for such taxable year was filed, the return due date for the taxable year, or the date on which the partnership filed an administrative adjustment request with respect to such year under section 6227, or in the case of any modification of an imputed underpayment under section 6225(c), the date that is 270 days (plus the number of days of any extension consented to by the Secretary under paragraph (7) thereof) after the date on which everything required to be submitted to the Secretary pursuant to such section is so submitted, or in the case of any notice of a proposed partnership adjustment under section 6231(a)(2), the date that is 330 days (plus the number of days of any extension consented to by the Secretary under section 6225(c)(7)) after the date of such notice. The period described in subsection (a) (including an extension period under this subsection) may be extended by an agreement entered into by the Secretary and the partnership before the expiration of such period. In the case of a false or fraudulent partnership return with intent to evade tax, the adjustment may be made at any time. If any partnership omits from gross income an amount properly includible therein and such amount is described in subparagraph (A) or (C) of section 6501(e)(1), subsection (a) shall be applied by substituting “6 years” for “3 years”. In the case of a failure by a partnership to file a return for any taxable year, the adjustment may be made at any time. For purposes of this section, a return executed by the Secretary under subsection (b) of section 6020 on behalf of the partnership shall not be treated as a return of the partnership. In the case of a partnership that is required to report any information described in section 6501(c)(8), the time for making any adjustment under this subchapter with respect to any tax return, event, or period to which such information relates shall not expire before the date that is determined under section 6501(c)(8). If a partnership fails to include on any return or statement any information with respect to a listed transaction as described in section 6501(c)(10), the time for making any adjustment under this subchapter with respect to such transaction shall not expire before the date that is determined under section 6501(c)(10).