Marvin Belzer, MD

Director, Division of Adolescent and Young Adult Medicine
Attending Physician
Professor of Pediatrics and Medicine, Keck School of Medicine of USC

Marvin Belzer, MD is an Adolescent Medicine physician who specializes in care for youth with HIV, transgender youth, and youth with chronic fatigue. He is a Professor of Clinical Pediatrics and Medicine who has been a USC faculty member for 24 years.

Dr. Belzer has provided care for youth at risk or living with HIV for 25 years and is a leading researcher on interventions to improve adherence to HIV medications. He is an internationally recognized leader in the field of transgender care for youth. In addition to providing information all over the world, Dr. Belzer has also appeared on MSNBC to educate audiences about the needs of transgender youth.

Clinical Interests

HIV; Gender Identity Disorder; Chronic Fatigue Syndrome; Medication Adherence


Medical School

University of Southern California Keck School of Medicine


University of California/Irvine Medical Center: Primary Care Internal Medicine


University of California/Irvine Medical Center: Primary Care Internal Medicine


Children's Hospital Los Angeles: Adolescent Medicine



Internal Medicine: American Board of Internal Medicine; Adolescent Medicine: American Board of Internal Medicine

Professional Memberships

Fellow, American College of Physicians, Fellow, Society for Adolescent Medicine, American Academy of HIV Medicine World Professional Association for transgender Health


Barbara Korsch Award for Medical Education


Belzer ME, Naar-King S, Olson J, Sarr M, Thornton S, Kahana SY, Gaur A, Clark L. The Use of Cell Phone Support for Non-Adherent HIV-Infected Youth and Young Adults: An Initial Randomized and Controlled Intervention Trial. AIDS and Behav (2013) DOI 10.1007/s10461-012-0661-3

Simons L*, Schrager SM, Clark LF, Belzer M, Olson J. Parental Support and Mental Health Among Transgender Adolescents. Journal of Adolesc Health. 2013:53:791 – 793.

Nadia Dowshen, MD1,2*, Meredith Matone, MHS1, Xianqun Luan, PhD1, Susan Lee1, Marvin Belzer, MD3, Maria Isabel Fernandez, PhD4, David Rubin, MD, MSCE1,2 and the Adolescent Medicine Trials Network for HIV/AIDS Interventions. Behavioral and Health Outcomes for HIV+ Young Transgender Women (YTW) Linked to and Engaged in Medical Care. LGBT Health. 2015 DOI: 10.1089/gbl.2014.0062

Marvin E Belzer, Karen Kolmodin-MacDonell, Leslie F Clark, Jennifer Huang, Johanna Olson, Shoshana Y Kahana, Sylvie Naar-King, Moussa Sarr, Sarah Thornton. Acceptability and Feasibility of a Cell Phone Support Intervention for Youth Living with HIV with Nonadherence to Antiretroviral Therapy. AIDS Patient Care and STDs.2015;19:338—345. DOI: 10.1089/apc.2014.0282

Olson J, Schrager S, Belzer M, Simons L, Clark L. Baseline Physiologic and Psychosocial Characteristics of Transgender Youth Seeking Care for Gender Dysphoria. Journal of Adolescent Health, July 2015 DOI: 10.1016/j.jadohealth.2015.04.027


Youth with HIV have been frequently shown to have poor adherence to their medications. This can lead to poor health, development of HIV strains resistant to medications and transmission of HIV to sexual partners. Dr. Belzer's team is developing innovative strategies to try to improve medication adherence for youth by incorporating the use of cell phones to provide needed support. He is also interested in improving healthcare for transgender youth, including hormone blocking medication during puberty and cross gender hormones later in adolescence.

Visit the Belzer Laboratory.


  • National Institute of Health (NIH) Adolescent Trials Network
  • Westat
  • University of Alabama Birmingham
  • University of Southern California  


  • NICHD Adolescent Medicine Trials Network for HIV-AIDS Interventions
  • NICHD International Maternal Pediatric Adolescent AIDS Clinical Trials
  • NICHD Support for Dr. Belzer to Chair the Clinic PI’s in the ATN Network

Research Studies

5,000 transgender women are testing a LifeSkills Mobile intervention web-app to see if it helps reduce condomless sex, increase PrEP use, and decrease HIV infections over several years.