Professional requirements for physicians specializing in pediatrics were estimated to assist policymakers in developing guidelines for graduate medical education. In estimating service requirements for pediatrics, the pediatrics Delphi panel reviewed reference and incidence-prevalence and utilization data for 230 conditions that affect the ambulatory care practices of the general child health care provider. After adjusting incidence-prevalence rates, panelists reviewed data on the percentage of persons with each condition requiring health care. Leading ambulatory problems were identified, and delegated visits by condition were estimated. Based on the panelists estimates, a total of over 35,000 general pediatricians should be required in 1990 to perform patient care activities. Since some physicians would be primarily engaged in nonpatient care (e.g., teaching, research, and administration), a total of 38,978 pediatricians were estimated to be required in 1990. After factoring in an anticipated supply of nonphysician health care providers, the modeling panel estimated that between 29,000 and 31,500 general pediatricians would be required in 1990. Appendices include: lists of members of the Delphi panels, and estimated prevalence rates and physician shares, including recommendations on ambulatory care service needs for pediatrics. A bibliography is included. (SW)