M. Susan Ridgely

Photo of M. Ridgely
Codirector, RAND Center of Excellence on Health System Performance; Senior Health Policy Researcher; Affiliate Faculty, Pardee RAND Graduate School
Santa Monica Office


J.D. in health law, University of Maryland School of Law


M. Susan Ridgely is a senior health policy researcher at the RAND Corporation and a Pardee RAND Graduate School affiliate faculty member. She has more than 25 years' experience in health services research and policy analysis.

She has led numerous grant and contract projects for government, foundation, and private funders. Her recent research activities include projects on innovation in health care financing, patient safety, and medical liability. She is codirector of the RAND Center of Excellence on Health System Performance, a five-year, multi-institutional center funded by AHRQ to characterize high-performing health systems and identify the most effective ways to promote the uptake of evidence-based practice in health care delivery systems. She is also collaborating on a study modeling health care cost containment options for California.

Ridgely completed studies of the cost and quality performance of California physician organizations, the IHA Bundled Episode Payment and Gainsharing Demonstration, and the Blue Shield of California's Accountable Care Organization (ACO) Infrastructure Grant Program. She was also the RAND principal investigator for the national evaluation of the AHRQ Patient Safety and Medical Liability Demonstration Program.

Ridgely employs site visit, interview, focus group, and survey methodologies to understand changes in the financing and delivery of health care, to derive "lessons learned," and communicate those lessons to policymakers and other stakeholders. She has co-authored over 75 peer-reviewed articles, law review articles, monographs, and reports in the health and behavioral health fields. Ridgely received her J.D. from the University of Maryland School of Law. 

Recent Projects

  • RAND Center of Excellence on Health System Performance
  • Evaluation of IHA Value-Based P4P on Reducing Total Cost of Care
  • Longitudinal Evaluation of HHS Patient Safety and Medical Liability Initiative
  • IHA Bundled Episode Payment and Gainsharing Demonstration
  • Blue Shield of California's ACO Infrastructure Grant Program

Selected Publications

Ridgely, M.S., Duffy, E., Wolf, L., Vaiana, M., Scanlon, D., Buttorff, C., Leitzell, B., Ahluwalia, S., Hilton, L., Agniel, D., Haviland, A., and Damberg, C, "Understanding U.S. health systems: Using mixed methods to unpack organizational complexity," eGEMs (Generating Evidence & Methods to improve patient outcomes), 7(1), 2019

Damberg, C., Silverman, M., Burgette, L., Vaiana, M. and Ridgely, M.S. , "Are value-based incentives driving behavior change to improve value? ," American Journal of Managed Care, 25(2), 2019

Waxman, D.A., Greenberg, M.D., Ridgely M.S., Kellerman, A., Heaton, P., "The effect of malpractice reform on emergency department care," New England Journal of Medicine, 371(16), 2014

Ridgely, M.S., Greenberg, M., Pillen, M. & Bell, J., "Progress at the intersection of patient safety and medical liability: Insights from the Patient Safety and Medical Liability Demonstration Program," Health Services Research, 51(supplement), 2016

Ridgely, M.S., De Vries, D., Bozic, K.J., Hussey, P.S., "Bundled payment fails to gain a foothold in California: The experience of the IHA Bundled Episode Payment and Gainsharing Demonstration," Health Affairs, 33(8), 2014

Damberg, C., Silverman, M., Burgette, L., Ridgely, M.S., "The response of physician organizations to value-based incentives to improve quality and reduce total costs of care," American Journal of Managed Care (forthcoming)

Honors & Awards

  • President's Award, RAND Corporation


  • U.S. currency wrapped around prescription bottle

    The Winding Path to Effective Bundled Payment

    It's not unusual for a demonstration to fall short of its original objectives. Learning from such cases is part of the innovation process. This is especially worthwhile for bundled payment, which has many potential benefits for patients, providers, and payers.

    Aug 29, 2014 Health Affairs Blog

  • An elderly woman sorting multiple prescriptions

    Could Liability Concerns Derail Clinical Decision Support?

    Computerized clinical decision support (CDS) systems have been developed to enhance physician decisionmaking and reduce the incidence of avoidable medical errors. Drug-drug interaction warnings are a mainstay of CDS systems, but they give rise to a fundamental problem that limits the utility of the systems to date.

    Jul 6, 2012

  • Clinical Decision Support and Malpractice Risk

    From the standpoint of policy makers, the basic challenge is to ensure that liability concerns do not derail the clinical value of new CDS technology, write Michael Greenberg and M. Susan Ridgely.

    Jul 6, 2011 The Journal of the American Medical Association