This study compares expenditures for physician services in a closed panel gatekeeper health maintenance organization (HMO) and an open panel point of service HMO that share the same physician network. The study uses administrative files of the two study HMOs for 1994-1995 to assess differences in spending for primary care physicians' (PCPs') services, specialists' services, and total physician services. When the copayments for PCP visits and PCP-referred specialist visits were $0, total physician expenditures were 4 percent higher in the gatekeeper HMO than in the point of service plan (p < .05). When the copayments for PCP visits and PCP-referred specialist visits were $10, total physician expenditures ranged from equal in both HMOs to 7 percent higher in the gatekeeper HMO (p < .01), depending on the copayment for self-referred visits. Expenditures for specialists' services were not higher in the point of service plan. The authors conclude that direct patient access to specialists does not necessarily result in higher physician or specialist expenditures in HMOs.