The purpose of this study was to test a theoretical model that integrated two explanations of nurse practitioner interaction and participatory decision making with physicians. The two explanations were derived from technology theory and social exchange theory. Nurse practitioners (N = 38) responded to a four-scale magnitude estimation instrument measuring each of four concepts in the model: complexity, expected benefit-cost ratio of interaction, interaction, and participatory decision making. Predictions derived from both theories were supported. Nurse practitioner decisions about interaction with physicians were influenced by the dynamics of social exchange with physicians, as well as the technological requirements of primary care. The findings offer nurse practitioners new strategies for managing professional exchanges on behalf of their patients.