Michael Horberg

Michael Horberg, MD, MAS, FACP, FIDSA

Associate Medical Director of Research, Medical Education, Community Health, Medicaid, HIV & STD, Genetics, Transgender Health, Infection Prevention and Control

Executive Director, Mid-Atlantic Permanente Research Institute
Director HIV/AIDS and STD, Kaiser Permanente and Care Management Institute



MAS, University of California, San Francisco
Residency, Categorical Internal Medicine, Michael Reese Hospital/University of Chicago
MD, Boston University School of Medicine
BA, Boston University

Academic Affiliations:

Professor of Medicine, Kaiser Permanente School of Medicine

Professional Affiliations:

Immediate Past Chair, Kaiser Permanente National Research Council
Chair, AHIP/CMS HIV and Hepatitis C Quality Measures Working Group
Co-chair, IDSA/HIVMA HIV Primary Care Guideline Committee
Incoming Chair, Health Care Systems Research Network
Past Chair, HIV Medicine Association
Past President, Gay and Lesbian Medical Association
Fellow, American College of Physicians
Fellow, Infectious Disease Society of America
Member, AcademyHealth

Michael Alan Horberg, MD, MAS, FACP, FIDSA is Associate Medical Director for Kaiser Permanente Mid-Atlantic Permanente Medical Group (MAPMG). In that role, he has responsibilities for Research, Medical Education, Community Health, Medicaid, Genetics, HIV and STD, Transgender Health, and Infection Control and Prevention. He serves as the Executive Director of the Mid-Atlantic Permanente Research Institute (MAPRI). As Executive Director, Dr. Horberg is responsible for all research activities in Kaiser Permanente Mid-Atlantic States (KPMAS). As Associate Medical Director for Medical Education, he is the Designated Institutional Official for KPMAS.

Dr. Horberg serves as the medical director for KPMAS Community Health, and is the Medicaid leader for MAPMG, including Chief Medical Officer for KPMAS in Maryland Medicaid, as well as helping lead clinical operational efforts in both Maryland and Virginia Medicaid, and serving on the KPMAS Medicaid Executive Committee. Michael leads HIV, STD, Infection Prevention, and transgender health care efforts in the KPMAS region, and HIV and STD care program-wide for Kaiser Permanente. This year, he is leading the opening of Pride Medical and KPMAS’ Gender Pathways programs and clinics within KPMAS. Dr. Horberg leads the Medical Genetics and Genomics strategy for MAPMG and is Executive Sponsor for KPMAS’ Commission on Cancer Accreditation and National Surgical Quality Improvement Program.

Dr. Horberg serves as director of HIV/AIDS program-wide for Kaiser Permanente and as Clinical Lead for HIV/AIDS and STDs for the Care Management Institute. Under President Obama, Dr. Horberg has served on the Presidential Advisory Council on HIV/AIDS, having co-chaired the Access to Care and Improved Outcomes Committee. Dr. Horberg is a Fellow of the American College of Physicians and the Infectious Disease Society of America (IDSA). He is Past-Chair of the Board of Directors of the HIV Medicine Association of IDSA. He has served on the IDSA Quality Performance Committee, and presently co-chairs the IDSA Primary Care Guideline Committee. Dr. Horberg has served as a commissioner on the State of Maryland Natalie M. LaPrade Medical Cannabis Commission. He is past-president of the national Gay and Lesbian Medical Association.

In his role as Executive Director of MAPRI, Dr. Horberg leads a department of both clinical and data research with over sixty team members. His HIV research interests are health service outcomes for HIV-infected patients (including HIV quality measures and care improvement, and determinants of optimized multidisciplinary care for maximized HIV outcomes), medication adherence issues in these patients, and epidemiology of the disease. Dr. Horberg serves as the MAPRI and national principal investigator for the Kaiser Permanente Research Bank (national genomics initiative). Other research interests include other sexually transmitted diseases and hepatitis. Dr. Horberg has published over 150 manuscripts and delivered over one hundred presentations at scientific meetings; all are in peer-reviewed literature or conferences. He has chaired multiple Expert Panels on HIV-related provider performance measures (including ones sponsored by CMS, NCQA, and IDSA), and has served on NIH and CDC peer-review panels.

A Chicagoan by birth, Dr. Horberg attended Boston University Medical School, and received his Master of Advanced Studies, from University of California San Francisco. He completed his residency in internal medicine (categorical) at University of Chicago Michael Reese Hospital and Medical Center. He is a resident of the District of Columbia with his husband Chip and their pet poodle Grant.

Research Interests:

  • Models of Care
  • HIV Care and Outcomes Quality Metrics
  • Registry Development
  • Pharmaceutical Safety and Comparative Effectiveness
Sexually Transmitted Disease:
  • Gay/Lesbian Health and STI risk
  • Syphilis
  • Registry Development
  • Hepatitis Care Quality Metrics

For a full list of publications, please see Dr. Horberg’s Curriculum Vitae.

  1. Lang R, Hogan B, Zhu J, McArthur K, Lee J, Zandi P, Nestadt P, Silverberg MJ, Parcesepe AM, Cook JA, Gill MJ, Grelotti D, Closson K, Lima VD, Goulet J, Horberg MA, Gebo KA, Camoens RM, Rebeiro PF, Nijhawan AE, McGinnis K, Eron J, Althoff KN; North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) of the International Epidemiologic Databases to Evaluate AIDS (IeDEA), “The Prevalence of Mental Health Disorders in People with HIV and the Effects on the HIV Care Continuum,” AIDS, 2023; 2023 Feb 1;37(2):259-269.
  2. Zalla LC, Cole SR, Eron JJ, Adimora AA, Vines AI, Althoff KN, Silverberg MJ, Horberg MA, Marconi VC, Coburn SB, Lang R, Williams EC, Gill MJ, Gebo KA, Klein M, Sterling TR, Rebeiro PF, Mayor AM, Moore RD, Edwards JK, “ Association of Race and Ethnicity with Initial Prescription of Antiretroviral Therapy Among People with HIV in the US,” JAMA. 2023; 2023 Jan 3;329(1):52-62.
  3. Jaurretche M, Byrne M, Happ LP, Levy M, Horberg M, Greenberg A, Castel AD, Monroe AK; DC Cohort Executive Committee, “HIV Care Continuum Outcomes among Recently Diagnosed People with HIV (PWH) in Washington, DC,” Epidemiol Infect. 2023; 2023 Jan 30;151:e45.
  4. Jetsupphasuk M, Hudgens M, Lu H, Cole S, Edwards J, Adimora A, Althoff K, Silverberg M, Rebeiro P, Lima V, Marconi V, Sterling T, Horberg M, Gill MJ, Kitahata M, Moore D, Lang R, Gebo K, Rabkin C, Eron J, “Optimizing Treatment for Human Immunodeficiency Virus to Improve Clinical Outcomes Using Precision Medicine,” American Journal of Epidemiology, 2023; 2023 Mar15: kwad057.
  5. Burrell T, Kim S, Mohadikar K, Jonas C, Ortiz N, Horberg M, “Family Structure and Adolescent Mental Health Service utilization During COVID-19 Pandemic,” Journal Adolescent Health, 2023; 2023 April 7: S1054-139X(23)00065-4.
  6. Lang R, Humes E, Coburn S, Horberg M, Fathi L, Watson E, Jefferson C, Park L, Justice A, Gordon K, Napravnik S, Edward J, Browne L, Silverberg M, Skarbinski J, Leyden W, Stewart C, Hogan B, Gebo K, Williams C, Althoff K, for the Corona-Infectious-Virus Epidemiology Team (CIVETs) of the NA-ACCORD of IeDEA, “Analysis of severe illness after SARS-CoV-2 breakthrough infection in people with and without HIV in the United States,” JAMA Network Open, 2022; 2022 Oct 3;5(10):e2236397.
  7. Lea A, Leyden W, Sofrygin O, Marafino B, Skarbinski J, Napravnik S, Agil D, Augenbraun M, Benning L, Horberg M, Jefferson C, Marconi V, Park L, Gordon K, Bastarache L, Gangireddy S, Althoff K, Coburn S, Gebo K, Lang R, Willsiams C, Silverberg M, “HIV Status, Tenofovir Exposure, and the Risk of Poor COVID-19 Outcomes: Real World Analysis from 6 United States Cohorts Prior to Vaccine Rollout,” Clinical Infectious Diseases, 2023; 2023 Mar 2;ciad084; online ahead of print.
  8. Miller M, Eberhart L, Jefferson C, Horberg M, “Beyond Antiretroviral Treatment: Patterns and Factors Associated with Composite Medication Adherence Before and During the COVID-19 Pandemic in Patients with HIV with Multiple Chronic Conditions,” JAIDS, 2023; 2023 Apr 15;92(5):405-413.
  9. Jefferson C, Watson E, Certa J, Gordon K, Park L, D’Souza G, Benning L, Abraham A, Agil D, Napravnik S, Sivlerberg M, Leyden W, Skarbinski J, Williams C, Althoff K, Horberg M, “Differences in COVID-19 Testing and Adverse Outcomes by Race, Ethnicity, Sex, and Health System Setting in a Large Diverse US Cohort,” PLOS One, 2022 Nov 23;17(11):e0276742.
  10. Byrne M, Akselrod H, Monroe A, Horberg M, Lucar J, Castel A, Denyer R, Doshi R, Secco A, Squires L, Schrofter S, Benator D, on behalf of the DC Cohort Executive Committee, “Identifying geographic areas of Washington DC with increased potential for sexual HIV transmission among People with HIV with STIs and concurrent elevated HIV RNA: Data from the DC Cohort,” Open Forum Infectious Diseases, 2022; Mar 18;9(5):ofac139.
  11. Avula H, Ambrosy A, Silverberg M, Reynolds K, Towner W, Hechter R, Horberg M, Vupputuri S, Leong T, Leyden W, Harrison T, Lee K, Sung SH, Go A, “Human Immunodeficiency Virus Infection and Risks of Morbidity and Death in Adults with Incident Heart Failure,” European Heart Journal (Open), 2021 Dec 1;1(3):oeab040.
  12. Lang R, Gill MJ, Coburn S, Grossman J, Gebo K, Horberg M, Mayor A, Sivlerberg M, Willig A, Justice A, Klein M, Bosch R, Rabkin C, Hogan B, Thorne J, Moore R, Althoff K, for the North American AIDS Cohort Collaboration on Research Design (NA-ACCORD) of the International Epidemiologic Databases to Evaluate AIDS (IeDEA), “The Changing Prevalence of Anemia and Risk Factors in People with HIV in North America Who Have Initiated ART, 2007-2017,” AIDS, 2022; e-pub ahead of print.
  13. Muiru A, Madden E, Scherzer R, Horberg M, Sivlerberg M, Klein M, Mayor A, Gill MJ, Napravnik S, Crane H, Marconi V, Koethe J, Abraham A, Althoff K, Lucas G, Moore R, Shlipak M, Estrella M, “Effect of Adopting the New Race-Free 2021 Chronic Kidney Disease Epidemiology Collaboration Estimated Glomerular Filtration Rate Creatinine Equation on Racial Differences in Kidney Diesase Progressio among People with Human Immunodeficiency Virus: An Observational Study,” Clinical Infecitous Diseases, 2022; e-pub ahead of print.
  14. Lam O, Leyden W, Leong T, Horberg M, Reynolds K, Ambrosy A, Avula H, Hechter R, Towner, W, Vupputuri S, Go A, Silverberg M, “Variation in Heart Failure Risk by HIV Severity and Sex in People with HIV Infection,” JAIDS, 2022; 92(2): 175-181.


  1. North American AIDS Cohorts Collaboration on Research and Design (NA-ACCORD). Administrative Supplement: Investigating PASC in integrated and non-integrated systems
    Goal: Purpose of the study are to compare PASC with accounting for pre-existing conditions and matching to COVID-negative population, comparing by HIV antibody status. Comparisons to another health system (Johns Hopkins Medicine) and by COVID vaccination status also will be studied.
    Funder: National Institute of Allergy and Infectious Diseases
    Role: Principal Investigator
  2. Vaccine Safety Datalink (VSD) Project
    Goal: This will be KPMAS joining the CDC VSD.
    Funder: CDC
    Role: Principal Investigator
  3. Measuring the Impact of COVID-19 among a Urban Cohort of PLWH in Washington DC
    Goal: Purpose is to better understand the interplay of COVID-19 among a population impacted by HIV infection within a defined population in Washington, DC.
    Funder: National Institute of Allergy and Infectious Disease, The George Washington University
    Role: Co-investigator
  4. Kaiser PrEP Data
    Goal: This will provide additional data and demographics to assess the United States’ use of HIV Pre-Exposure Prophylaxis and study the demographics and opportunities for its use within the USA.
    Funder: US Center for Disease Control
    Site Principal Investigator
  5. Assessing Syndemics of Cardiovascular Disease in People with and without HIV
    Goal: This study will explore the role social demographic and community factors in the impact of HIV on heart disease and visa versa. It also will explore use of KP Research Bank to data and blood samples to explore the role of genetics in these morbidities.
    Funder: National Heart, Lung, and Blood Institute
    Role: Co-investigator
  6. Cabotegravir PrEP: Actionable Robust Evidence for Translation into Practice (CABARET)
    Goal: This study will explore what factors contribute to employment of long-acting HIV Pre-Exposure Prophylaxis and how can this best be encouraged and grown in use to prevent HIV infection within and integrated care system.
    Funder: National Institutes of Mental Health
    Role: Co-investigator
  7. The DC Cohort: A Longitudinal Population-Based Cohort Study of People Living With HIV in Washington, DC
    Goal: The goals of this study are 1) enhance the Cohort database to incorporate new data sources to comprehensively describe and monitor HIV and co-occurring conditions; 2) expand the use of the existing DC Cohort Clinical Dashboard to monitor HIV care outcomes as well as key indicators related to ending the HIV epidemic; and 3) use the Cohort as a platform from which to develop pioneering interventions to improve the quality of care of PLWH.
    Funder: National Institute of Allergy and Infectious Disease
    Role: Co-investigator
  8. Kaiser Permanente Research Bank
    Goal: In this study, KP Research Bank aims to recruit 280K members total across all KP regions to increase the overall Research Bank collection to 500K. Members will be consented to provide a biospecimen and complete a survey. This region will participate in the recruitment and other Research Bank-related efforts, including scientific, strategic and operational.
    Funder: Kaiser Permanente Mid-Atlantic Community Benefits
    Principal Investigator
  9. North American AIDS Cohorts Collaboration on Research and Design (NA-ACCORD)
    This is the North America response to IeDEA, and for which Kaiser Permanente Northern California participates. It is a collaborative cohort compendium and analysis for purposes of achieving sufficient power to address issues that could not be adequately addressed by single cohorts.
    National Institute of Allergy and Infectious Diseases
    Role: Site Principal Investigator
  10. Kaiser Permanente HIV Quality Improvement and Performance Program
    Goal: We seek to determine quantitative measures of HIV care and outcomes in Kaiser Permanente, which has never been done on a systematic basis in a managed care organization previously.  We seek to then initiate quality improvement programs where we determine there are opportunities for improvement.
    Funder: Care Management Institute/The Permanente Federation/Kaiser Health Plans
    Role: Principal Investigator
  11. HIV Infection, Use of Tenofovir and Other Antiretrovirals, and Risk of Fatal and Non-Fatal Comorbidities: Cohort study in Kaiser Permanente
    Goal: The purpose of the overall study is to primarily compare the incidence rate of fatal and non-fatal comorbidities in HIV patients with incidence rates among matched HIV-uninfected controls, and HIV-uninfected individuals prescribed PrEP.
    Funder: Gilead, Inc.
    Role: Co-Principal Investigator
  12. COMpAAAS Tripartite: ART-CC, KP, and VA
    Goal: The purpose of the overall study is to participate in a scientific collaboration across three grant partners to assemble data sets, including electronic health record data.  Partners will interpret and disseminate results of the study through conference abstracts and manuscripts.
    Funder: National Institute of Health
    Role: Site Principal Investigator