In most states, child support paid on behalf of Temporary Assistance for Needy Families (TANF) participants is used to offset TANF and child support administrative expenditures; this policy primarily benefits taxpayers. In contrast, Wisconsin allowed most custodial parents to keep all support paid on their behalf. This policy, which treats welfare and child support as complements, was evaluated through an experimental design. This paper reports the key results of the experimental evaluation, using state administrative data to examine the effects on child support outcomes and governmental cost. We find that when custodial mothers keep all child support paid on their behalf, paternity establishment occurs more quickly, noncustodial fathers are more likely to pay support, and custodial families receive more support. These outcomes are achieved at no significant governmental cost. © 2008 by the Association for Public Policy Analysis and Management.