The period after completing primary and adjuvant cancer treatment until recurrence or death is now recognized as a unique phase in the cancer control continuum. The term "survivorship" has been adopted to connote this phase. Survivorship is a time of transition: Issues related to diagnosis and treatment diminish in importance, and concerns related to long-term follow-up care, management of late effects, rehabilitation, and health promotion predominate. In this article, we explore the unique challenges of care and health service delivery in terms of the interface between primary care and specialist care during the survivorship period. The research literature points to problems of communication between primary and specialist providers, as well as lack of clarity about the respective roles of different members of the health-care team. Survivorship care plans are recommended as an important tool to facilitate communication and allocation of responsibility during the transition from active treatment to survivorship. Research questions that remain to be answered with respect to survivorship care plans and other aspects of survivorship care are discussed.