An inadequate number of trained primary care clinicians limits access to care at Community Health Centers. If family practice residents working in these centers can provide care to patients at a cost that is comparable to the center's hiring its own physicians, then expansion of Family Practice Residency Programs into community centers can address both cost and access concerns. A cost-benefit analysis of the Family Practice Residency Program at the Fresno, CA, community center was performed; the community center is affiliated with the University of California at San Francisco. Costs included (a) residents' salaries, (b) supervision of the family practice residents, (c) family practice program costs for educational activities apart from supervision at the community center, and (d) administrative costs attributable to family practice residents in the community center. Benefits were based on the number of patients that residents saw in the community center. Using this approach, a cost of $7,700 per resident per year was calculated. This cost is modest compared with the cost of training residents in inpatient settings. The added costs attributable to training residents in community health centers can be shared with agencies that are concerned with medical education, providing physicians to underserved communities, and increasing the supply of primary care physicians. Redirecting graduate medical education funding from hospitals to selected ambulatory care training centers of excellence would facilitate placing residents in community centers. This change would have the dual advantage of addressing the current imbalance between training in ambulatory care and hospital sites and increasing the capacity of community health centers to meet the health care needs of underserved populations.