joint return
(3) Special rules for married couples (A) In general Except in the case of a husband and wife who lived apart at all times during the taxable year, if the taxpayer is married at the close of the taxable year, subsection (a)(2)(B) shall apply only if the taxpayer and his spouse file a joint return for the taxable year. (B) Application of paragraph (1) In the case of a joint return— (i) paragraph (1) (other than subparagraph (C) thereof) shall be applied separately with respect to each spouse, but (ii) paragraph (1)(C) shall be applied with respect to their combined adjusted gross income. (C) Determination of marital status For purposes of this subsection, marital status shall be determined under section 7703(a). (D) Joint return For purposes of this subsection, the term “joint return” means the joint return of a husband and wife made under section 6013.