Little research exists on the contributions that noncustodial fathers make to children they have had in different families. We use baseline survey data from an intervention for noncustodial parents who are behind in their child support payments to examine formal and informal payments. We explore whether noncustodial fathers who have had children with multiple mothers provide any support to children from older relationships, and whether they provide less to these children than to children from their most recent relationship (their youngest nonresident child). We find that fathers are more likely to provide informal support to their youngest child, but many fathers are also providing to their oldest child; the likelihood of formal payments does not differ. The results suggest that fathers may prioritize younger children rather than trade families; these have important implications for understanding the role of the formal child support system.