Despite nurses' substantial role in care coordination, few education programs exist to better support them in this role. Identification of a set of core care coordination activities across heterogeneous care coordination programs would facilitate the development of a standard of practice. We sought to examine care coordination activities across two care coordination programs in Family Medicine Groups in Quebec, and their relationship to the program design. We performed a comparative case study of two care coordination programs in primary care targeting frequent users of healthcare services and people with Alzheimer's disease and related disorders. Data collection included documents and semi-structured interviews with key informants. Several activities were common to both programs, such as patient identification; assessment, development of an individualized service plan; and linking patients and caregivers with professionals and services. However, their components were different due to the impact of the integrated care program design, policy environment, and the target patient populations' complex needs. The homogeneity or heterogeneity of patients' complex needs shapes their care trajectory and the intensity of their care coordination needs. As the complexity of these needs grows, so does the necessity to build the care coordinators' capacity for integrated care.