alimony or separate maintenance payment

(i) such payment is received by (or on behalf of) a spouse under a divorce or separation instrument (as defined in section 121(d)(3)(C)),

(ii) in the case of an individual legally separated from the individual’s spouse under a decree of divorce or of separate maintenance, the payee spouse and the payor spouse are not members of the same household at the time such payment is made, and

(iii) there is no liability to make any such payment for any period after the death of the payee spouse and there is no liability to make any payment (in cash or property) as a substitute for such payments after the death of the payee spouse.

(i) such payment is received by (or on behalf of) a spouse under a divorce or separation instrument (as defined in section 121(d)(3)(C)),

(ii) in the case of an individual legally separated from the individual's spouse under a decree of divorce or of separate maintenance, the payee spouse and the payor spouse are not members of the same household at the time such payment is made, and

(iii) there is no liability to make any such payment for any period after the death of the payee spouse and there is no liability to make any payment (in cash or property) as a substitute for such payments after the death of the payee spouse.

(1) In general

Notwithstanding subsection (c)(1)(B), (c)(4), or (d)(1)(C), if—

(A) a child receives over one-half of the child's support during the calendar year from the child's parents—

(i) who are divorced or legally separated under a decree of divorce or separate maintenance,

(ii) who are separated under a written separation agreement, or

(iii) who live apart at all times during the last 6 months of the calendar year, and—

(B) such child is in the custody of 1 or both of the child's parents for more than one-half of the calendar year, such child shall be treated as being the qualifying child or qualifying relative of the noncustodial parent for a calendar year if the requirements described in paragraph (2) or (3) are met.

(2) Exception where custodial parent releases claim to exemption for the year

For purposes of paragraph (1), the requirements described in this paragraph are met with respect to any calendar year if—

(A) the custodial parent signs a written declaration (in such manner and form as the Secretary may by regulations prescribe) that such custodial parent will not claim such child as a dependent for any taxable year beginning in such calendar year, and

(B) the noncustodial parent attaches such written declaration to the noncustodial parent's return for the taxable year beginning during such calendar year.

(3) Exception for certain pre-1985 instruments

(A) In general

For purposes of paragraph (1), the requirements described in this paragraph are met with respect to any calendar year if—

(i) a qualified pre-1985 instrument between the parents applicable to the taxable year beginning in such calendar year provides that the noncustodial parent shall be entitled to any deduction allowable under section 151 for such child, and

(ii) the noncustodial parent provides at least $600 for the support of such child during such calendar year.

For purposes of this subparagraph, amounts expended for the support of a child or children shall be treated as received from the noncustodial parent to the extent that such parent provided amounts for such support.

(B) Qualified pre-1985 instrument

(A) such payment is received by (or on behalf of) a spouse under a divorce or separation instrument,

(B) the divorce or separation instrument does not designate such payment as a payment which is not includible in gross income under this section and not allowable as a deduction under section 215,

(C) in the case of an individual legally separated from his spouse under a decree of divorce or of separate maintenance, the payee spouse and the payor spouse are not members of the same household at the time such payment is made, and

(D) there is no liability to make any such payment for any period after the death of the payee spouse and there is no liability to make any payment (in cash or property) as a substitute for such payments after the death of the payee spouse.