Researchers at Brigham and Women’s Hospital will expand an evaluation of the innovative payment initiative currently being tested in five primary care practices in Albany, N.Y., and Boston, Mass. Under this medical home–based reimbursement model, primary care physicians are paid a comprehensive, risk-adjusted, per-patient annual fee, augmented by a bonus tied to performance on quality and efficiency. With early results indicating cost-savings for the Albany practices, the participating payer, Capital District Physician Health Plan, will spread the reimbursement model to a total of 24 sites in 2012. This evaluation will assess changes in quality, utilization, and health care costs in the 24 primary care sites in the Albany region. In addition, the evaluation team will complete the analysis of the five original sites included in phase 1.