We introduce a primary care practice model for caring for patients with multimorbidity. Primary care for these patients requires flexibility and ongoing coordination, and it often must be tailored to individual circumstances. Such complex and flexible care could be accomplished within communities of practice, whose participants are willing to learn from their shared practice, further each other's goals, share their stories of success and failure, and promote the continued evolution of collective learning. Primary care in these communities would be conceived as a complex adaptive process in which the participants use an iterative approach to care improvement that integrates what they learn and do collectively over time. Clinicians in these communities would define common goals, cocreate care plans, and engage in reflective case-based learning. As community members manage their knowledge, gain insights, and develop new care strategies, they can improve care for patients with multiple conditions. Using a mix of methods, future research should explore the conditions that are necessary for collective learning within communities of clinicians who care for patients with multimorbidity and who develop new knowledge in practice. By understanding these conditions, we can foster the development of collective learning and improve primary care for these patients.