‘‘(B) INDIVIDUALS WHO SUPPORT THEM-
SELVES.—An individual shall not be a quali-
fying child of a taxpayer if such individual pro-
vides over half of such individual’s own support 
for the calendar year in which the taxable year 
of the taxpayer begins. 
‘‘(C) ONLY
EXEMPTION
AMOUNT.—An 
individual who is a qualifying child of any tax-
payer shall not be treated as the dependent of 
any taxpayer for purposes of this part. 
‘‘(6) SPECIAL RULE RELATING TO 2 OR MORE 
CLAIMING QUALIFYING CHILD.— 
‘‘(A) IN GENERAL.—Except as provided in 
paragraph (7), if an individual would (but for 
this paragraph) be a qualifying child of 2 or 
more taxpayers for taxable years beginning in 
the same calendar year, such individual shall be 
treated as the qualifying child of the taxpayer 
who is— 
‘‘(i) a parent of the individual, or 
‘‘(ii) if none of such taxpayers is a 
parent of the individual, the taxpayer with 
the highest adjusted gross income for such 
taxable year.
‘‘(B) PARENTS
NOT
FILING
JOINT
RE-
TURNS.—If an individual would (but for this 
paragraph) be a qualifying child of both parents 
of such individual and such parents do not file 
a joint return together, such child shall be 
treated as the qualifying child of— 
‘‘(i) the parent with whom the child 
resided for the longest period during the 
taxable year, or 
‘‘(ii) if the child resides with both par-
ents for the same length of time during 
such taxable year, the parent with the 
highest adjusted gross income. 
‘‘(C) FOSTER CHILDREN.—For purposes of 
this paragraph, the taxpayer shall be treated as 
a parent of any eligible foster child who has the 
same principal place of abode as the taxpayer 
for more than one-half of such taxable year. 
‘‘(7) SPECIAL RULE FOR CERTAIN PRE-2006 IN-
STRUMENTS.— 
‘‘(A) IN GENERAL.—Notwithstanding para-
graph (6), a child who has parents who— 
‘‘(i) are divorced or legally separated 
under a decree of divorce or separate 
maintenance,
‘‘(ii) are separated under a written 
separation agreement, or 
‘‘(iii) live apart at all times during the 
last 6 months of the calendar year, 
shall be treated as being the qualifying child of 
the noncustodial parent for a calendar year if 
the requirements of subparagraph (B) are met. 
‘‘(B) REQUIREMENTS.—For purposes of 
subparagraph (A), the requirements of this sub-
paragraph are met if— 
‘‘(i) such child would, but for this 
paragraph, be the qualifying child of the 
custodial parent, and 
‘‘(ii) a qualified pre-2006 instrument 
between the parents is applicable to such 
child for the taxable year beginning in such 
calendar year. 
In the case of an agreement executed before 
January 1, 1985, the requirements of this sub-
paragraph are met only if, in addition to meet-
ing the requirements of clauses (i) and (ii), the 
noncustodial parent provides at least $600 for 
the support of such child during such calendar 
year.
‘‘(C) QUALIFIED PRE-2006 INSTRUMENT.— 
For purposes of this paragraph, the term 
‘qualified pre-2006 instrument’ means any writ-
ten declaration referred to in subsection (e)(2) 
(as in effect on the day before the date of the 
enactment of the Child Definition Simplification 
Act of 2004)— 
‘‘(i) which is executed before January 
1, 2006, and 
‘‘(ii) which is not modified on or after 
such date in a modification which expressly 
provides that this subsection shall not 
apply to such declaration. 
‘‘(D) CUSTODIAL PARENT AND NONCUSTO-
DIAL
PARENT.—For purposes of this sub-
section— 
‘‘(i) CUSTODIAL PARENT.—The term 
‘custodial parent’ means the parent with 
whom a child shared the same principal 
place of abode for the greater portion of 
the calendar year. 
‘‘(ii) NONCUSTODIAL
PARENT.—The 
term ‘noncustodial parent’ means the par-
ent who is not the custodial parent.