This article is from the Financial Aid, Scholarships, and Fellowships FAQ, by Mark Kantrowitz with numerous contributions by others.
If your parents are separated or divorced, the custodial parent is
responsible for filling out the FAFSA. The custodial parent is the
parent with whom you lived the most during the past 12 months.
Note that this is not necessarily the same as the parent who has
legal custody. If you did not live with one parent more than the
other, the parent who provided you with the most financial support
should fill out the FAFSA. This is probably the parent who claimed
you as a dependent on their tax return. If you have not received
any support from either parent during the past 12 months, use the
most recent calendar year for which you received some support from
a parent or lived with either parent.
Note, however, that any child support and/or alimony received from
the non-custodial parent must be included on the FAFSA.
Financial aid applications can be somewhat confusing because there
are several different criteria applied for different kinds of
1. The parent with whom the child lived the most during the past
2. The parent who provided the most financial support to the child
during the past 12 months.
3. The parent who provided more than half the child's support (and
will continue to do so).
4. The parent who has legal custody.
5. The parent who claimed the child as a dependent on their tax
As noted above, criteria 1 and 2 are used for determining the
custodial parent, with the first criteria being primary.
For determining household size (the number of family members),
criteria 3 is the most important. However, the student's custodial
parent gets to list him or her even if the custodial parent does
not provide more than half of the student's support. This leads to
the anomalous situation where a student can be counted as
belonging to two different households. For example, suppose the
non-custodial parent remarries and has college-aged children of
his own. If the non-custodial parent provides more than half of
the student's support, he gets to list the student as a member of
his household even though the custodial parent has also listed the
student as a member of her household. (The IRS tax return
instructions prevent this kind of double dipping on tax returns,
but the FAFSA instructions apparently don't.)
Criteria 3 is also used to determine whether the student has one
or more dependents, in the rules for specifying whether the
student is an independent student with dependents.
Criteria 4 and 5 are not used in the financial aid formulas, but
are sometimes used to give an indication of the right choice when
the other criteria are insufficient. Criteria 5 is also sometimes
used to substantiate claims made under criteria 3. For example, a
financial aid administrator may ask a parent for a copy of their
tax return, to see whether they claimed the child as a
dependent. Criteria 5 usually implies criteria 3, because the IRS
definition of a dependent includes a 50% support test. There IRS
definition includes a few exceptions where the parent isn't
required to provide more than half the child's support in order to
claim the child as a dependent, but in almost every case, if the
parent could not claim the child as a dependent (criteria 5), they
did not provide more than half the child's support (criteria 3).