The growth of physician-organization arrangements (e.g., PHOs, MSOs) by physician specialty groups and delivery organizations is widely acknowledged. Yet, little is known about these new organizational forms. This paper presents a descriptive analysis of physician-organization arrangements (POAs) using survey data obtained from 79 organizations. The analysis examines the extent to which healthcare delivery organizations are engaged in the development of POAs, the number of physicians involved in POAs, and the decision-making control and strategies associated with POAs. These attributes are examined for the sample as a whole and relative to the institutional and market conditions facing study participants. Results are discussed in terms of their implications for health services managers.