The authors compare health care use and outcomes of a panel of persons with rheumatoid arthritis receiving health care in prepaid group practice and feefor- service settings. In 1982, they randomly sampled one half of all 114 boardcertified or eligible rheumatologists in Northern California. Those who participated provided the names of all patients with rheumatoid arthritis presenting during a 1-month period; 812 of these patients (97% of those listed) were interviewed. In 1984,745 of them (92% of the baseline cohort) were interviewed; 569 receive care in fee-for-service settings and 176 in prepaid group practice. As in the baseline survey year, the prepaid patients received similar amounts and kinds of health care as their fee-for-service counterparts. The prepaid and feefor- service patients achieved similar outcomes, as measured by symptoms of illness, functional status, and work disability. The fee-for-service patients reported poorer overall health status. The authors conclude, after 2 years of followup study, that patients in prepaid group practice receive similar medical care inputs and achieve outcomes at least as good as those in fee-for-service.