Community-based organizations (CBOs), typically small and underfunded with transient staff members, are told by funders to care for clients and verify program value. To assist CBOs with evaluations that speak to program effectiveness, many funders wish to expand the evaluation capacity of CBO staff members so that evaluation will occur as long as programs exist. In this article, the authors argue that sustainable program evaluation is unlikely when resources are devoted to training staff members to conduct evaluation in house or when money is spent for a typical external evaluation. Instead, the authors recommend a model they name "insourcing." The insourcing model, a cross between in-house and outsourced evaluation, spreads the cost burden of the external evaluation across many CBOs while keeping evaluation in the hands of those trained in the art of evaluation. Insourcing also reduces the staff burden inevitable with internal evaluation and has the greatest potential to sustain. This article compares insourcing with other evaluation types and discusses circumstances in which insourcing could be beneficial. (Contains 2 tables and 2 notes.)