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Executive Officers

Taejoon Ahn, MD MPH CPE
Taejoon Ahn, MD MPH CPE
President & Chief Executive Officer

Taejoon Ahn, M.D. became the president of John Muir Medical Group (JMMG) in January of 2014. He leads a medical group of over 350 clinicians, mostly in primary care. JMMG is the exclusive contracted provider of primary care services for John Muir Health, partnering closely for over 25 years. Prior to the presidency, Dr. Ahn served as vice president and medical director of urgent care services for JMMG. He also worked as faculty for the University of California, San Francisco's National HIV/AIDS Clinicians' Consultation Center. He is currently an Assistant Clinical Professor of Family & Community Medicine for UCSF.

Dr. Ahn has also served as director on the board of John Muir Health and is currently serving as Director on the board of Canopy Health. Canopy Health is a joint venture between multiple provider groups to offer a large network in the San Francisco Bay Region.

Dr. Ahn is the current Chair of the Medical Practice Affairs Committee for the California Academy of Family Physicians and also serves on the CAFP Audit/Compliance Committee. He has also served on CAFP’s Board of Directors, Legislative Affairs Committee as Chair and for the California Medical Association’s specialty delegation and council on legislation.

Dr. Ahn received his medical degree from the University of California San Francisco, where he also completed a residency in Family & Community Medicine. He received his Masters in Public Health with an emphasis in Epidemiology from UC Berkeley. He is an alumnus of the California Healthcare Foundation's Leadership Fellowship and is a certified physician executive with the American Association for Physician Leadership (formerly the American College of Physician Executives).

Ravi Hundal, MD
Ravi Hundal, MD
Chief Financial Officer and Executive Vice President of Clinical Integration & Population Health

Ravi Hundal, MD is an accomplished family physician with over 25 years of experience in the health care industry. Dr. Hundal is currently the Chief Financial Officer and Executive Vice President of Clinical Integration John Muir Medical Group (JMMG) an organization with 350 plus physicians. As the CFO/EVP Dr. Hundal is primarily responsible for managing the company’s finances, including financial planning, management of financial risks, and financial reporting. Dr. Hundal also sits on the following boards, John Muir Health from 2013 to current, America’s Physicians Group a national medical group organization, and he chairs the John Muir Health Clinically Integrated Network/ACO Board.

His previous executive positions include, JMMG voting board member from 1999-2010, Board member of John Muir Physicians Network from 2009 to 2013, and Board member of Seven Hills School from 1999 to 2005.

Dr. Hundal received his medical degree from Autonomous University of Guadalajara, and completed his family medicine residency at Contra Costa Regional Medical Center in Martinez, CA. He also received his bachelor’s degree in Biology from the University of California Davis.

In his spare time Dr. Hundal enjoys wine, food, and traveling with his wife Dr. Marie McGlynn and spending time with his family. He also enjoys various sports including lacrosse, soccer, and hockey.

Deborah Arce, MD PhD
Deborah Arce, MD PhD
Chief Operating Officer and Senior Vice President and Chair of Ambulatory, Inpatient and Transitional Care Services

Deborah Arce, M.D., Ph.D. serves as Senior Vice President and Chair of Inpatient and Transitional Care Services for John Muir Medical Group (JMMG).  In this role, Dr. Arce manages the operation of the hospitalist programs at John Muir Medical Centers in Concord and Walnut Creek.  She also provides administrative oversight of the Skilled Nursing Facility, Home Visit and Post-Discharge Clinic programs.  In 2018, Dr. Arce assumed responsibility for the Medical Consultation service at the John Muir Behavioral Health Center. 

In 2021, Dr. Arce was named Interim Chief Operational Officer of Ambulatory Services.  Her primary role is oversight of the leadership teams who manage the clinical practices, Urgent Care, Palliative Care, the Comprehensive Care Clinic and the Care at Home program.

Dr. Arce serves as an ex officio member of the John Muir Health Board of Directors. She served 3 terms on the JMMG Board of Directors.

Dr. Arce received her medical degree from the University of California, San Francisco, where she also completed a residency in Primary Care Internal Medicine.  She received a Master of Science degree from the University of California, Berkeley, and a Ph.D. from the University of California, Davis.