In this volume of a larger study, the Graduate Medical Education National Advisory Committee (GMENAC) reports the potential impact of nonphysician providers on physician requirements in 1990. The report has two major thrusts: (1) a description of the "state of the art" regarding what was known about nonphysician providers, and (2) recommendations as to what is desirable, as well as feasible, with respect to nonphysician providers in the different specialties. Sections include: an overview of panel's charges; a summary of work; principles and concepts, such as the definition of nonphysician health care provider; the interim report; the relationship of the nonphysician panel to the modeling process; expanded charge; and background data for the panel's recommendations. Numerous recommendations are cited such as: a careful study of requirements for nurse practitioners, physician assistants, and nurse-midwives should be undertaken as soon as possible; five percent of the normal, uncomplicated deliveries (197,600) should be delegated to nurse-midwives in 1990; and the effect of the size of the physician supply on nonphysician utilization should be studied. References and attachments are provided. (LC)