Our Physicians
Our Story
Our founding physicians were partners of Alta Emergency Medical Group (AEMG) and staffed the Alta Bates Hospital Emergency Department in Berkeley, CA during the 1970s to the early 1990s. These included Drs. Greenly, Gary, Roberts, McAmis, Schrager, Zelin, Sornsin, Golomb, Carothers, Rosenthal, Bradshaw, Schumb, Larsen and many others whose vision, dedication and energy set the foundation for our group’s downstream success. In 1995, AEMG became Berkeley Emergency Medical Group (BEMG).
In 2004, we merged with the emergency physicians staffing Summit Medical Center Emergency Department in Oakland. This was the result of consolidation of various service lines between Sutter Health’s two hospital campuses in Berkeley and Oakland collectively known as Alta Bates Summit Medical Center.
A truly democratic physician group was organically created, including a structure to assure full transparency and accountability in all areas of our business and medical practice, as well as rapid progression to truly equal ownership. BEMG established our long-standing commitment to promote a culture whereby all physicians have a voice and are supported as members of our BEMG family. Here, they can continue to grow to reach their fullest potential and to best serve our patients, our medical center, and our community.
Leadership Team
Brian Potts, MD MBA
President
Dr. Potts graduated from UC-Irvine School of Medicine in 2004 with a MD-MBA combined degree with Distinction in Service. He completed Emergency Medicine Residency at UC-Irvine Medical Center in 2007. He has been with BEMG since 2007.
James Hirshberg, MD
Chief Financial Officer
Dr. Hirshberg graduated from the University of Michigan Medical School in 2003 and completed his residency in Emergency Medicine at The Ohio State University in 2008. He has been with BEMG since 2008.
Jeff Chen, MD
Medical Director, Alta Bates
Dr. Chen graduated from UC Berkeley and then earned his MD/MPH degree at Tufts University. He completed residency at Yale New Haven Hospital and finished an Emergency Ultrasound fellowship at Highland/ACMC. He has been with BEMG since 2006.
Claire Lyons, MD
Assistant Medical Director,
Alta Bates
Dr. Lyons graduated from the University of San Francisco in June 2014. She completed her residency at the Highland Emergency Medicine Residency program. She joined BEMG in 2018.
John Skovran, DO
Medical Director, Summit Campus
Dr. Skovran did his undergraduate studies at Colby College, Waterville, ME and worked in Washington, DC as a science consultant for Booz Allen Hamilton. He attended medical school at Lake Erie College of Osteopathic Medicine, PA and completed his residency at Einstein Medical Center, PA. He has been with BEMG since 2015.
Emily Sze, MD
Assistant Medical Director,
Summit
Dr. Sze graduated from the University of Maryland School of Medicine in 2015. She completed her residency at Hackensack University Medical Center in New Jersey. She joined BEMG in 2018.
Our Physicians
Aaron Barber, MD
Dr. Barber graduated from Iowa College of Medicine in 1994 and completed his residency in Emergency Medicine from New York University/Bellevue Medical Center in 1998. He has been with BEMG since 2011.
Austin Causey, MD
Dr. Causey graduated from Rush Medical College in 2016. He completed his residency in Emergency Medicine at the University of Illinois, Chicago in June 2019. He joined BEMG in 2020.
Lisa Cheng, MD
Dr. Cheng graduated from The Chicago Medical School in 2003 and completed Emergency Medicine Residency at Denver Health in 2007. She has been with BEMG since 2007.
Kristina Field, MD
Dr. Field graduated from Creighton University School of Medicine in May of 2018. She completed her residency training in Emergency Medicine at Maricopa County Hospital in 2021. She joined BEMG in 2022.
Robert Gorski, MD
Dr. Gorski graduated from Michigan State University College of Human Medicine in May 2004. He completed his residency in Emergency Medicine at the Presbyterian Brooklyn Methodist in May 2004. He joined BEMG in 2020.
Sarah Kelmenson-Chau, MD
Dr. Kelmenson graduated from University of Pennsylvania School of Medicine in 2003 and completed her residency in Emergency Medicine from Brown University in 2007. She has been with BEMG since 2007.
Enyioma Okechukwu, MD
Dr. Okechukwu attended undergrad at the University of Michigan and medical school at New York Medical College. She completed her residency at Regions Hospital- Healthpartners institute in St. Paul, MN in 2019. She joined BEMG in 2023.
Jillian Rosenblum, MD
Dr. Rosenblum graduated from University of Arizona, Tucson, AZ. She completed her residency in Emergency Medicine at the Cook County Health and Hospital system, Chicago, IL in 2015. She joined BEMG in 2019.
James Starr, MD
Dr. Starr graduated from University of Wisconsin Medical School in 1998 and completed his residency in Emergency Medicine from St. Luke’s/Roosevelt Hospital Center, NY in 2001. He has been with BEMG since 2005.
Adrian Thomas, MD/MS
Adrian Thomas, MD/MS, graduated from the UC Berkeley-UCSF Joint Medical Program in 2016. He completed his residency in Emergency Medicine at the Riverside Community Hospital / University of California Riverside program in 2020. He joined BEMG in 2020.
Ami Yamamoto, MD
Dr. Yamamoto obtained a Bachelor of Science degree in Materials Science and Engineering at Massachusetts Institute of Technology, and her medical degree at Drexel University College of Medicine. She completed her Emergency Medicine residency at Harbor UCLA Medical Center. She has been with BEMG since 2015.
Ronn Berrol, MD
Dr. Berrol graduated from the University of California Davis with a B.S. in Biochemistry and did his Residency at UC Irvine Medical Center. He has been with BEMG since 1993.
David Chen, MD
Dr. Chen graduated from Albert Einstein College of Medicine in 2006. He completed Emergency Medicine Residency at Jacobi-Montefiore in New York in 2010. He has worked with BEMG since 2011.
Hyacinth DeGuzman, MD
Dr. DeGuzman, graduated from Georgetown University in 2003 and completed Emergency Residency in 2007 at Lincoln Medical Center in New York. She has been with BEMG since 2008.
Myles Fisher, DO
Dr. Fisher graduated from Oklahoma College of Osteopathic Medicine in 2016. He completed his residency in Emergency Medicine at Integris Health, Oklahoma City in June 2020. He joined BEMG in 2021.
Zachary Grunwald, MD
Dr. Grunwald graduated from Yale School of Medicine in 2019. He completed his residency training in Emergency Medicine at Temple University Health System in Philadelphia, PA and joined BEMG in 2022.
Joshua Kim, MD
Dr. Kim graduated medical school from Kansas City University of Medicine and Biosciences in 2017. He completed his residency training at Cook County Health, Chicago, IL in 2021. He joined BEMG in 2021.
Dominic Pappas, MD
Dr. Pappas graduated from Hofstra Medical School in Long Island, NY in 2020 and completed his residency at Maricopa Medical Center in Phoenix Arizona in 2023. He has been with BEMG since 2023.
Mordecai Pavlovsky, MD
Dr. Pavlovsky completed medical school at SUNY Downstate Medical Center in Brooklyn NY in 2009. He graduated from his Emergency Medicine Residency at Einstein Medical Center in Philadelphia, PA. He has been with BEMG since 2014..
Michael Roth, MD
Dr. Roth graduated from Wayne State University School of Medicine in 2017. He completed his residency in Emergency medicine at the Ascension St. John Hospital and Medical Center in June 2020. He joined BEMG in 2020.
Joshua Stein, MD
Dr. Stein graduated from Northwestern University Feinberg School of Medicine in 2018. He completed his residency training in Emergency Medicine at Stanford University in 2022. He joined BEMG in 2022.
Marcus Williams, MD
Dr. Williams graduated from University of California, Irvine, School of Medicine in 2012. He completed his residency in Emergency Medicine at the Alameda County Medical Center in 2016. He joined BEMG in 2020.
Brian Yokers, MD
Dr. Yokers graduated from Touro University College of Osteophatic Medicine in 2010. He completed his residency at St Joseph’s Regional medical center in Paterson NJ. He joined BEMG in 2018.
Stephanie Brown, MD, MPH
Dr. Brown graduated from the University of Chicago Pritzker School of Medicine in 2009, and completed her Emergency Medicine residency at Los Angeles County/Harbor-UCLA Medical Center in 2012. She has been with BEMG since 2014.
Yenting Chen, MD
Dr. Chen graduated from University of California, Davis School of Medicine in 2004 and completed his Emergency Medicine Residency at Denver Health Medical Center in 2008. He has been with BEMG since 2008.
Chris Dutra, MD
Dr. Dutra graduated from UC Davis School of Medicine in 1979. He completed an Internal Medicine residency at Kaiser Oakland in 1983 and an Emergency Medicine residency at Highland Hospital. He has been with BEMG since 2003.
Arti Gehani, MD
Dr. Gehani graduated from Drexel University College of Medicine in 2006 and completed her residency in Emergency Medicine at University of Southern California in 2010. She has been with BEMG since 2013.
Paul Hanna, MD
Dr. Hanna graduated from University of Tennessee Health Science Center College of Medicine in May of 2020. He completed his residency training at Maricopa County Hospital in 2023. He joined BEMG in 2023.
Samantha Honner, MD
Dr. Honner graduated from residency in emergency medicine at Alameda County Medical Center in 2008, with the Andy Levitt Academic Resident of the Year award. She has been with BEMG since 2008.
Keala Landry, MD
Dr. Landry graduated from New York Medical College and completed her residency at Yale New Haven Hospital. She has been with BEMG since 2008.
Joseph Pinizzotto, DO
Dr. Pinizzotto graduated from Touro University California College of Osteopathic Medicine in 2018. He completed his residency in Emergency Medicine at Einstein Medical Center Philadelphia in 2022. He joined BEMG in 2022.
Steve M. Sornsin, MD
Dr. Sornsin graduated from Ohio State University School of Medicine in 1983 and Denver General Hospital (now Denver Health System) Emergency Medicine Residency Program in 1987. He has been with BEMG since 1995.
Noor Tarabishy, MD
Dr. Tarabishy graduated from Wayne State School of Medicine in 2019 and completed her residency in Emergency Medicine at Ascension St. John Hospital in 2022. She joined BEMG in 2023. She has been with BEMG since 2023.
Christopher Wu, MD
Dr. Wu graduated from the University of California with a Bachelor of Arts in Public health in 2010. He went on to graduate from the University of Arizona in Medicine followed by completion of residency in Emergency Medicine in 2016.
Karen Carothers, MD
Dr. Carothers received her MD at Tufts Medical School in Boston, MA and completed her residency in emergency medicine at Highland General Hospital in Oakland, CA. She joined BEMG in 1993.
Aurelia Cheng, MD
Dr. Cheng graduated from Case Western Reserve University School of Medicine in May of 2015. She completed her residency training in Emergency Medicine at MetroHealth Medical Center/Cleveland Clinic/Case Western Reserve University School of Medicine in 2018. She joined BEMG in 2022.
Dylan Easley, MD
Dr. Easley graduated from Indiana University School of Medicine in 2003 and completed his residency in Emergency Medicine at New York Methodist Hospital/Weill-Cornell in 2006. He has been with BEMG since 2006.
Robert Golomb, MD
Dr. Golomb graduated from Brown University in 1981, did General Surgery residency in New York City and Emergency Medicine residency at Highland Hospital in Oakland. He has been with BEMG since 1995.
Jaan Hasan, MD
Jaan Hasan, MD graduated from American University of the Caribbean in Sint Maarten in 2019 and completed his residency in emergency medicine at Wyckoff Heights Medical Center in Bushwick, Brooklyn in 2023. He has been with BEMG since 2023.
Katia Johnston, MD
Dr. Johnston graduated from the University of Colorado School of Medicine in 2018. She completed her residency training at Cook County Health and Hospital Systems in Chicago, IL in 2022, serving as a chief resident in her final year. She joined BEMG in 2022.
Jessica Li, MD
Dr. Li graduated from Johns Hopkins School of Medicine and completed residency at Highland Hospital. She has been with BEMG since 2016.
Tim Richardson, MD
Dr. Richardson graduated from Tulane University school of Medicine in 2015. He completed his residency in Emergency Medicine at the Cook County Health and Hospital System in 2019. He joined BEMG in 2019..
Douglas Spurr, MD
Dr. Spurr graduated from Albert Einstein Medical School in 1991. He completed his Internal Medicine internship in 1992 and Emergency Medicine residency in 1995 at Bronx Municipal Hospital Center. He has been with BEMG since 2008.
Grace Tarng, MD
Dr. Tarng trained at Texas Tech University and completed her residency in El Paso, Texas. She has been with BEMG since 2015.
Alan Xi, MD
Dr. Xi graduated from Oakland University William Beaumont School of Medicine, Michigan in 2013, and completed his residency in Emergency Medicine at Stanford Hospital in California in 2021. He has been with BEMG since 2023.