Custodial and noncustodial parents.

The custodial parent is the parent with whom the child lived for the greater number of nights in 2025. The noncustodial parent is the other parent. If the child was with each parent for an equal number of nights, the custodial parent is the parent with the higher adjusted gross income. See Pub. 501 for an exception for a parent who works at night, rules for a child who is emancipated under state law, and other details.