Adoption of the most effective methods of contraception requires individual decision-making and negotiation with c o n t r a c e p t i v e providers. In order to take account of both behavioral elements, a twodimensional framework for understanding contraceptive adoption and continuation by unmarried young is proposed, incorporating a "socialp s y c h o l o g i c a l m o d e l " of i n d i v i d u a l decision-making and an ù interpersonal model" of factors affecting provider-client interaction. The social-psychological model is based on an earlier value-expectancy theory of behavior motivation as applied to health-related behaviors. The interpersonal model is derived from conflict-bargaining perspectives on professional-client interaction; it is suggested that expectations for this interaction are based on a limited number of internalized "models": the ùprofessional"; the " b u r e a u c r a t i c " ; the " c o m m e r c i a l " ; and the Preparation of this paper was supported in part by Grant Number RO1 HD 13623 from the Center for Population Research, National Institute of Child Health and Human Development. Dr. Nathanson is Associate Professor, Department of Population Dynamics, School of Hygiene and Public Health, The Johns Hopkins University. Dr. Becker is Professor, Department of Health Behavior and Health Education, School of Public Health, The University of Michigan. Requests for reprints should be addressed to Dr. Nathanson, Department of Population Dynamics, Johns Hopkins University Schooi of Hygiene and Public Health, 615 North Wolle Street, Baltimore, MD 21205. ~Readers interested in the apendization of specific variables may write to the senior author for copies of research instruments based on the theoretical framework described in this paper. Space limitations do not permit a discussion of aperational issues in the paper itself. ùparental." Insofar as client and professional "models"disagree, communication may break down and client understanding and/or acceptance of provider advice cannot be assured. The components of the social-psychological and interpersonal models are described in detail, and a combined framework is proposed.The majority of pregnancies among unmarried young women are unintended and could be substantially reduced in number by consistent use of contraception; yet close to two-thirds of sexually active young women in the United States are either nonusers or sporadic users of contraceptive methods (Zelnik & Kantner, 1980). The reasons for erratic contraceptive use when pregnancy is not intended are unclear; however, the consequences of such behavior are potentially most serious when the partners are young and unmarried (Card & Wise, 1978;Trussell & Menken, 1978).Although identification and measurement of factors associated with contraceptive continuation have long been issues of concern, development of a substantive framework on which to base explanation and prediction of variation in contraceptive behaviors has lagged behind accumulation of data (Karr, 1971);Kasl, 1973), and...