This paper describes physician and physician extender (i.e., a person who renders services under the supervision and responsibility of a physician) supply and distribution and provides projections of the supply. It addresses inequities of access to health care by examining the relationship to disparities in physician distribution by specialty and geography. The first of eight sections gives the 1976 active physician supply (as determined by American Medical Association and American Osteopathic Association data) as 362,970. Primary, secondary, and tertiary-care physician supply is investigated, and data on osteopathic doctors, women, minorities, foreign medical graduates, and specialty manpower is presented. Section 2 reviews the intern/resident supply for the groups mentioned above. In section 3 characteristics of physician extenders, such as physician assistants and nurse practitioners, are examined. Section 4 looks at the geographic distribution of physician and physician extenders. The fifth section projects the medical specialist supply. A first-year residency illustration shows that primary medical doctor care to population ratio might be expected to increase from sixty-five to eighty-five per 100,000 from 1974 to 1990. Section 6 discusses projected increases in the physician extender supply. Areas for further research are identified in section 7. The final section highlights policies, strategies, and priorities which impact on physician and physician extender supply and distribution. (This publication is an updated version of ED 144 512.) (CSS)