The Johns Hopkins ACG System offers a unique approach to measuring morbidity that improves accuracy and fairness in evaluating clinician performance, identifying patients at high risk, forecasting health care utilization and setting equitable payment rates.

Based on the premise that clustering of morbidity is a better predictor of health care services resource use than the presence of specific diseases or disease hierarchies, the ACG System provides a multi-morbidity framework that is clinically logical, informative of future health care resources, easy to use and applicable to both financial and clinical managers.



The ACG System Team is characterized by excellence in both research and practice. Incubated at the Johns Hopkins Bloomberg School of Public Health, the Team has been creating risk measurement and case mix categorization methodology for more than 30 years. The diverse ACG System Team, comprised of Johns Hopkins faculty and staff including clinicians, health services researchers, and Health Information Technology experts, has virtually “written the book” on risk adjustment through numerous contributions in the published literature.

  • Kumar Subramaniam, M.B.A.; Executive Director LEARN MORE
  • Steve Sutch, M.App.Sc., B.Sc., Dr.PH.; Director of Product Development LEARN MORE
  • Alan Thompson, M.Sc.; Director of User Support; UK Team Leader LEARN MORE
  • Melissa White Davis; Director, Product Marketing & Business Development LEARN MORE
  • James Barrett, M.A., M.B., B.Chir., M.Sc.; Senior Analyst, UK LEARN MORE
  • Nihat Yurt, M.D.; Senior Consultant, Eurasia LEARN MORE
  • Harriet Martyn, M.S.P.H.; Senior Consultant LEARN MORE
  • Walter Fenner, M.B.A.; Program Manager LEARN MORE
  • Giulianna Peri, M.M.I.S.; Communications LEARN MORE



Founded and led by one of the ACG System co-developers, the Center for Population Health IT (CPHIT) is a first-of-its-kind interdisciplinary center at The Johns Hopkins University, the vision of which is to make Johns Hopkins a global leader in population-centric Health IT (HIT) research and development. The Center focuses on improving the health and well-being of populations by advancing state-of-the-art Health IT and related internet and mobile-based e-health tools within public and private health care organizations and systems. The following are some of the Johns Hopkins researchers and clinicians involved in continuous R&D to improve the ACG System.

  • Jonathan P. Weiner, DrPH; Executive Director of Research and ACG System Co-developer. LEARN MORE
  • David Bodycombe, ScD, MSc; Director ACG System Research LEARN MORE
  • Thomas Richards, MS; ACG System Senior Research Analyst LEARN MORE
  • Klaus Lemke, PhD, MSc; ACG System Senior Research Analyst LEARN MORE
  • Hsien-Yen Chang, PhD; ACG System Research Analyst LEARN MORE

Risk Stratification: Identifying geriatric frailty from EHR unstructured data


The following third-party products enhance and add specific functionality (such as report generation) to the ACG System software, strengthening the end-user’s experience and results. Click on any of the below images to view detailed information about those products.

ACG System Compatible Reporting Tools



Generic Reporting Tools (need configuration)



ACG System Compatible Models



National Quality Forum (NQF) Certified Tools



Electronic Medical Records Software:




For questions about extending the ACG System functionality to better fit your specific needs, or if you have an Extension you would like featured on this page, please contact your account manager, or fill out the contact form.

Inclusion of the above resources does not imply an endorsement of the companies or the products/services they provide. See Terms page for details.

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