Team-based care involving physician assistants and/or nurse practitioners (PA/NPs) in the patient-centered medical home is one approach to improving care quality. However, little is known about how to incorporate PA/NPs into primary care teams. Using data from a large physician group, we describe the division of patients and services (e.g., acute, chronic, preventive, other) between primary care providers for older diabetes patients on panels with varying levels of PA/NP involvement (i.e., no role, supplemental provider, or usual provider of care). Panels with PA/NP usual providers had higher proportions of patients with Medicaid, disability, and depression. Patients with physician usual providers had similar probabilities of visits with supplemental PA/NPs and physicians for all service types. However, patients with PA/NP usual providers had higher probabilities of visits with a supplemental physician. Understanding how patients and services are divided between PA/NPs and physicians will assist in defining provider roles on primary care teams.