Teenagers' utilization of family planning services is of major concern in view of the estimated 4.1 million adolescent females at risk, defined as fertile, sexually active teenagers who are not pregnant and who are not seeking to become pregnant. To obtain information regarding teenagers' use of medical family planning services in clinical settings, the National Reporting System for Family Planning Services operated, from 1972-1978, a full-count survey of clinic-based visits for medical family planning services in the United States, Guam, Puerto Rico, and the Virgin Islands. A random sample of family planning service sites (N=1,195) participated in the 1978 survey, which studied visits made specifically for medical services associated with famly planning; visits for replenishing contraceptive supplies, counseling, pregnancy, or venereal disease tests were excluded. This document reports data from this survey, providing information, with tables and graphs, in the following areas: age, race, and ethnicity; visit status; education and income; pregnancy history; prior contraceptive method; contraceptive method adopted or continued; medical services provided; and geographic region. The appendices contain technical information on survey methodology, data collection and processing, and reliabiltiy of estimates; definitions of terms used in the report; and a copy of the Clinic Visit Record which was used to collect survey data. (WAS)