J. Michael McWilliams, M.D., Ph.D., is an associate professor in the Department of Health Care Policy at Harvard Medical School, and a practicing general internist at Brigham and Women’s Hospital in Boston. His research focuses on health care spending, quality, access, and disparities in aging populations with chronic conditions. He is currently completing two career development awards, a Paul B. Beeson Career Development Award in Aging Research from the National Institute on Aging and the American Federation for Aging Research, and a Clinical Scientist Development Award from the Doris Duke Charitable Foundation. In addition, he is principal investigator or co-investigator in several ongoing studies related to accountable care organizations (ACOs), measurement of low-value care in Medicare, organizational determinants of technology diffusion, risk adjustment of prospective payments and quality measures, and the effects of provider consolidation on health care prices. In prior research, he has examined the effects of Medicare prescription drug coverage on non-drug medical spending, the effects of Medicare coverage on health care and outcomes for previously uninsured adults, and the influence of cognition on enrollment decisions in Medicare.