In 1977, an estimated 4.2 million women received contraceptive services from organized family planning programs in the United States. The number of patients has grown each year since the late 1960s, but since 1973, growth has slowed concurrently with a diminished increase in the level of federal funding for family planning services. The proportion of clinic patients who are teenagers increased from 20 percent in 1969 to 31 percent in 1977. An estimated 1.3 million adolescents received services in 1977, compared with just 214,000 in 1969. Contraceptive services were provided during 1977 by 2,574 agencies at some 5,300 clinic sites. Health departments served 42 percent of all family planning patients; Planned Parenthood affiliates served 27 percent; hospitals served 13 percent; and community action groups, free clinics, neighborhood health centers and women's health programs together served 18 percent. Federal expenditures for medical family planning services provided by organized clinics and private physicians rose from an estimated $13.5 million in 1968 to $239.1 million in 1977. Estimated federal expenditures for clinic services were $192.5 million--three-quarters of the total $252.6 million in public and private expenditures for such programs. Federal project grant funds under Title X of the Public Health Services Act accounted for 42 percent of all medical family planning expenditures in clinics, and for 55 percent of all federal funds expended for this purpose. These findings are based on data from the most recent study of the organized family planning service network conducted by The Alan Guttmacher Institute (AGI) for 1977.(ABSTRACT TRUNCATED AT 250 WORDS)