Using a longitudinal sample of 522 biological, never-married, nonresident fathers from the Fragile Families and Child Wellbeing Study, this article examines the factors associated with fathers' coparenting 36 months after a birth. Ordinary least squares regression models indicate never-married, nonresident fathers are less likely to perceive high coparental supportiveness if they have ever been incarcerated, if they have completed high school, if they have a greater number of children with the child's mother, if the mother has lower levels of education, if they are not in a relationship with the focal child's mother, if they have a new partner, and if they see their child more frequently. In contrast, more supportive coparental relationships are perceived among fathers with higher incomes, with higher education, who are employed, with a male child, and who provide informal support. This study provides continuing evidence that several aspects of nonresident men's lives have important influences on their coparenting. (Contains 2 tables.)