Little information exists about the capabilities required to achieve the ultimate aims of accountable care -- better, less costly care that improves the health of populations -- or about how to measure the "readines" of providers to implement this new model. This paper reports on 59 hospital-based organizations that were members of a collaborative created to support the transition to accountable care. Assessment of 42 capabilities, divided further into 154 specific operating activities, found that the overall state of readiness was modest. Several characteristics appear to be associated with greater readiness to form an accountable care organization (ACO), including a strong patient-centered focus, full or partial ownership of a health plan, and positive relationships with providers in the market, among others. Variation in the patterns of readiness suggests that organizations are pursuing different paths toward accountable care. Additional study of organizations farther along the journey to accountable care is needed.