The functions of primary care, including care coordination, cannot be accomplished by the lone physician, no matter how dedicated. Primary care teams are a central tenet of the patient-centered medical home, a comprehensive model for delivering primary care. As primary care practices are redesigned to take advantage of the complementary skills of a variety of team members, care coordinators will take their place as indispensable members of the team. Current medical home demonstration projects across the country are experimenting with divided payment models that incorporate per-patient per-month capitated fees to enable practices to make investments in nonphysician team members. A substantial hurdle facing these projects is the costs of transforming the typical small primary care practice into a medical home. Even if payments are robust enough to support the ongoing expenses of a primary care team, they are unlikely to cover the substantial 1-time costs of redesigning workflow, reconfiguring offices, recruiting and training new staff, and retraining the current workforce. If the potential of the medical home is confirmed, our nation must be prepared to make an investment to support the transformation of primary care practice.