An organization comprises a group of collaborating agents (individual agents or nested organizations) that exhibit complex behaviors. Of particular interest are dynamic organizations that form and dissolve as their members' needs change. Such organizations are important in many applications, in cluding scientific and business computing. Contracts among autonomous agents have long been used to facilitate their collaboration. This paper provides a contracts-based approach for managing organizations. The proposed approach places organizations within institutions, themselves modeled as specialized organizations. Commitments form the basis of contracts and this paper establishes some important dynamic aspects by providing a commitment life cycle analysis. This approach has been applied in a prototype tool to manage organizations.