Leadership

      

Andrew A. Zimmerman, M.D.
President, Anesthesia Service Medical Group, Inc. (“ASMG”) Board of Directors
CEO, Anesthesia Management Professionals, Inc. (“AMP”)

Dr. Zimmerman joined ASMG in 1999, following four years in the U.S. Navy where he achieved the rank of Lieutenant Commander, and four years in academics at Washington University and the University of Washington. Dr. Zimmerman is a board-certified pediatric cardiac anesthesiologist practicing at Rady Children’s Hospital of San Diego, where he served as Department Chair from 2012 to 2013 and as Chief of Staff from 2015 to 2017. He also served as Chair of ASMG’s Insurance Committee from 2003 to 2017 and joined the ASMG Board in 2010, assuming the role of President in 2018. Dr. Zimmerman is also the CEO of ASMG’s wholly-owned practice management company, Anesthesia Management Professionals (“AMP”), and is Vice Chair of the AMP Board.

     

Yolanda Marzan, M.D.
Vice President, ASMG Board of Directors

Dr. Marzan joined ASMG in 2016, practicing at Sharp Chula Vista Medical Center where she served as Anesthesia Department Chair from 2020 to 2024, in addition to serving on ASMG’s Quality Improvement and Compliance Committee since 2021. She has been a member of the ASMG Board since 2022 and assumed the role of Vice President in 2024.

      

Theo B.M. van den Helder, M.D.
Secretary, ASMG Board of Directors

Dr. van den Helder joined ASMG in 1999, beginning his practice at Alvarado Hospital where he served as Department Chair from 2004 to 2005, before moving to Sharp Chula Vista Medical Center in 2011 where he served as Department Chair and Medical Director, and then to Scripps Green Hospital in 2015.  He has been a member of the ASMG Board since 2020, and assumed the role of Secretary in 2023.

      

Sepehr S. Tabibzadeh, M.D.
Treasurer, ASMG Board of Directors

Dr. Tabibzadeh joined ASMG in 2005, practicing at Sharp Memorial Hospital where he served as Subgroup Chief from 2014 to 2016.  He has been a member of the ASMG Board since 2017, and assumed the role of Treasurer in 2022.

      

Robert S. Dyer, M.D.
Member, ASMG Board of Directors

Dr. Dyer joined ASMG in 2011, practicing at Scripps Memorial Hospital Encinitas where he has served as the OB Anesthesia Liaison, as well as Subgroup Chief from 2021 to 2024, before joining the ASMG Board in 2024.

      

Paul J. Himaya, M.D.
Member, ASMG Board of Directors

Dr. Himaya joined ASMG in 2003, practicing at Scripps Memorial Hospital La Jolla where he has also served as a member of the Anesthesia Supervisory Committee since 2010, and as the department scheduler since 2020, in addition to serving on ASMG’s Claims Committee since 2019. He has been a member of the ASMG Board since 2023.

      

Edward Sherer, M.D.
Member, ASMG Board of Directors

Dr. Sherer joined ASMG in 2013, beginning his practice at Sharp Grossmont Hospital, before moving to Scripps Mercy Hospital in 2015 where he served as Anesthesia Department Chair from 2021 to 2024. He has been a member of the ASMG Insurance Committee since 2021, and joined the ASMG Board in 2024.

      

Mark S. Ransom, M.D.
Chair, Anesthesia Management Professionals (“AMP”) Board of Directors

Dr. Ransom joined ASMG in 1997 while practicing at Tri-City Medical Center, before moving his practice to Carlsbad Surgery Center in 2008 where he became Medical Director. Dr. Ransom also chaired ASMG’s Contracting & Compliance Committee before joining the ASMG Board in 2008, and served as ASMG’s President from 2012 to 2018.  He has served as Board Chair of AMP, ASMG’s wholly-owned practice management company, since 2018.

      

Michael C. Martin, M.D.
Member, AMP Board of Directors

Dr. Martin joined ASMG in 1988, and practices at Scripps Memorial Hospital La Jolla where he served as Department Chair from 2013 to 2017. He served on the ASMG Board of Directors from 1993 to 2004, during which time he was President from 1994 to 1998, and he currently serves on the AMP Board.

      

Glenn E. Buberl, Esq.
General Counsel, AMP

Mr. Buberl joined ASMG’s practice management staff in 1999 and became General Counsel of AMP in 2006, overseeing ASMG’s self-insured malpractice trust, compliance program, and all other legal matters.  Mr. Buberl also serves on the AMP Board of Directors.

      

Jeremy W. Dendle, J.D.
Chief Operating Officer, AMP

Mr. Dendle joined ASMG’s practice management staff in 1997, received his law degree in 2002, and became Chief Operating Officer of AMP in 2006, overseeing contracts, outside billing vendors, and general group operations.  Mr. Dendle also serves on the AMP Board of Directors.

      

Glen T. Lewandowski, C.P.A.
Chief Financial Officer, AMP

Mr. Lewandowski joined ASMG’s practice management staff in 1999 and became Chief Financial Officer of AMP in 2006, overseeing accounting, payroll, investments, and all other financial matters.  Mr. Lewandowski also serves on the AMP Board of Directors.