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Andrew Posselt


Bariatric and transplant surgeon

Dr. Andrew Posselt, a bariatric and transplant surgeon, is co-director of the Pancreatic Islet Transplantation Program at UCSF Medical Center. He specializes in adult and pediatric kidney, liver and pancreas transplantation, as well as laparoscopic and open (traditional) bariatric surgery.

In addition to caring for patients, Posselt conducts research on pancreatic islet cell transplantation, a procedure that can allow people with type 1 diabetes to discontinue insulin therapy. He also investigates mechanisms by which a transplant recipient's body rejects or tolerates tissue from a donor who isn't genetically identical, and he studies the metabolic and biochemical consequences of bariatric surgery.

Posselt earned his medical degree and a doctorate in immunology from the University of Pennsylvania. He completed residencies in internal medicine and general surgery as well as a transplant fellowship at UCSF, before joining the staff in 2003.

Posselt is a member of several professional and honorary societies, and has given presentations on transplant issues related to patient care and research. At UCSF, he supervises residents and fellows in transplant services and general surgery.

  • Education

    University of Pennsylvania School of Medicine, 1993

  • Residencies

    UCSF Medical Center, Internal Medicine, 1996

    UCSF Medical Center, Surgery, 2000

  • Board Certifications

    Surgery, American Board of Surgery

  • Academic Title


  • Languages





"I really try to consciously take my time with patients. If they have questions, I'll listen."

Where I see patients (6)

    My reviews


    Overall Experience
    98 Ratings
    About our process
    Oct 20, 2023
    Good experience
    Jan 30, 2023
    All the Drs. That I have seen there are wonderful and kind.
    Jan 28, 2023
    Dec 30, 2022
    Dec 10, 2022
    Dr Posselt was/is wonderful. Easy to talk to answers our questions and explains things well.
    Oct 20, 2022
    UCSF is the best health care I have received and I have received care at Kaiser Permanente and Stanford.
    Aug 25, 2022
    Aug 24, 2022
    Very good experience
    Aug 03, 2022
    Continued quality care. Thank you.
    Apr 23, 2022
    Excellent doctor listen carefully and his explanations are easy to understand
    Mar 17, 2022
    Mar 04, 2022
    Once I finally was contacted for the appointment it was fine.

    Selected research

    My work

    Living donor gives patient with liver cancer another chance

    Amy was running out of treatment options when a family friend offered to donate part of her liver. Dr. Posselt was on the team that made her surgery a success.

    Q&A: A unique path to transplant surgery

    Dr. Posselt shares his journey to becoming a surgeon at UCSF, as well as his insights on islet transplants for diabetes, organ transplantation and bariatric surgery.