Meet The Team
Executive Management / Physician Leadership
Leadership can be hard to define and it means different things to different people. Our leaders set direction and help themselves and others to do the right thing to move forward. To do this they create an inspiring vision, and then motivate and inspire others to reach that vision.
Irv Edwards, M.D., FACEP
Founder & President
Dr. Irv Edwards obtained his Bachelor's Degree from McGill University and his Medical Degree from the University of Calgary in Alberta, Canada. He came to Los Angeles to pursue his interest in Emergency Medicine and interned at Los Angeles County Hospital. After his internship, Dr. Edwards completed his residency in Emergency Medicine at Harbor UCLA Medical Center. Following his residency, Dr. Edwards pursued private practice at a variety of hospital sites in Los Angeles and Orange Counties including Chino Valley Medical Center, Encino-Tarzana Regional Medical Center, La Palma Intercommunity Hospital, Mission Community Hospital, Montclair Hospital Medical Center, Olympia Medical Center, Sherman Oaks Hospital, and Valley Presbyterian Hospital. He was the Director of Performance Improvement at Mission Community Hospital from 1998 – 2003 and he currently serves as the Director of Case Management at Mission Community Hospital and as the Chief of Staff at Chino Valley Medical Center. He is the Director of Emergency Services at Chino Valley Medical Center, Encino-Tarzana Regional Medical Center, Mission Community Hospital, and Montclair Hospital Medical Center.
In 1989, Dr. Edwards founded Emergent Medical Associates and has served as its President since inception. Since 2001, Dr. Edwards has been a dedicated member of CAL/ACEP and he currently sits on their Executive Board. He served as its President from 2005-2006.
Mark R. Bell, M.D., FACEP
President
Dr. Mark Bell has been a managing partner in EMA since 1998. As Co-President, he has led the start-up and management of several emergency departments, and developed along the way a unique skill set centered on creating department efficiencies and managing the critical role emergency departments serve in driving hospital performance. He developed the EMA administrative residency program which prepares EMA physicians for administrative roles. His expertise covers customer service, strategic planning, business development, and community service. Dr. Bell is an active physician, hospital advocate, and represents his colleagues in healthcare issues on a local as well as national level.
Mark is a graduate from the Chicago Medical School. His undergraduate training was at Westmont College, in Santa Barbara, California. He completed residency in emergency medicine at the University California Irvine in 1996 and is a fellow of the American College of Emergency Physicians. Following residency, Dr. Bell went into private practice in the South Bay of Los Angeles and soon partnered with Dr. Irv Edwards at Emergent Medical Associates. Through a dedication to quality, service, and efficient patient care, their emergency department management company grew from 5,000 patient visits per year, to more than 700,000 over the next decade. Mark is also the President and co-founder of Benchmark Hospitalists, a hospitalist company based in Los Angeles, and managing partner of Pipeline Health. He sits on various boards including the Marconi Foundation, Huntington Beach Hospital, Norris Cancer Leadership Board, and Goals for Life. Dr. Bell’s expertise is particularly strong in emergency department and in-patient efficiencies, customer service, paramedic outreach, strategic planning, and business development. Mark spends much of his time teaching physicians the skills required to succeed in administrative management and leadership. He has published on many topics, including pediatric cardiology, nutrition, and emergency medicine reimbursement, and frequently lectures on subjects most interesting to him such as The History of Nuclear Biological and Chemical Warfare, EMTALA, the Field Management of the Unknown Overdose, and the effect of efficient hospital care on morbidity and mortality. When he’s not working, Dr. Bell enjoys surfing, cycling, rugby, and traveling with his family. He’s married to Dr. Camela Ott, and has two children Luke and Dominic.
Lee R. Weiss, M.D., FACP, FACEP
Chief Clinical Operations Officer
Dr. Lee R. Weiss is currently Medical Director of Emergency Medical Services at Huntington Beach Hospital and Co-Medical Director of the Department of Emergency Medicine at Centinela Freeman Medical Center in Inglewood, CA.
A graduate of the State University of New York at Downstate School of Medicine, Dr. Weiss trained in Internal Medicine, Immunology, Infectious Diseases, and Emergency Medicine at SUNY Downstate, Kings County Hospital, the National Institutes of Health, SUNY Stony Brook, Bellevue Hospital, and the New York University Medical Center.
Dr. Weiss previously was the Director of Emergency Medical Services at Knox Community Hospital in Mount Vernon, OH, and most recently Vice Chairman of the Department of Emergency Medicine at St. Vincent’s Medical Center in Bridgeport, CT. Dr. Weiss previously held faculty positions in the Departments of Medicine and Emergency Medicine at New York University School of Medicine, The Bellevue Hospital Center, and The Ohio State University School of Medicine.
Dr. Weiss is the founder and previous managing partner of Synergy Micro Systems in Columbus, OH. For the past twenty plus years, Dr. Weiss has focused his research interests on the Epidemiology and Management of Outpatient Infectious Diseases. His major research focus has been the epidemiology of resistance in Streptococcus pneumonia.
An avid international traveler, for the past twenty years, Dr. Weiss has volunteered with Doctors without Borders in Africa and Central Asia. Dr. Weiss resides with his wife Dr. Michelle Weiss and son Gavin in Hermosa Beach, CA.
G. Scott Brewster, M.D., FACEP
Chief Medical Officer
Dr. G. Scott Brewster is Chief Medical Officer at EMA and leads all quality program development including clinical best practice implementation and standardization. Dr. Brewster also oversees clinical leadership development in the organization and created the EMA Administrative Emergency Medicine Fellowship which was the first in the country at its inception. He has extensive hospital administrative experience including an long tenure as Emergency Medicine Director at Providence Tarzana Medical Center.
Dr. Brewster attended medical school at Northwestern University and completed an Internal Medicine and Emergency Medicine residency at UCLA. He is an actively practicing Emergency Physician and maintains his board certification in both Internal Medicine and Emergency Medicine. Prior to joining EMA in 2003, Dr. Brewster was a faculty member at UCLA and Cedars Sinai Medical Center.
Jason Greenspan, M.D., FACEP
Associate Chief Medical Officer
Raised in Southern California, Dr. Jason Greenspan received his Bachelor’s degree from the University of California, Berkeley and his MD from the University of Southern California. He then completed his residency training in Emergency Medicine at LAC+USC Medical Center, where he was Chief Resident.
Ari L. Nagler
Chief Executive OfficerAri Nagler has spent the last two decades building high-performing teams and efficient companies in healthcare, service, retail and hi-tech. He's a previous business owner and M&A executive having closed over 50 transactions for himself and his clients. He possesses a B.S. degree with emphasis in Management and Organizational Development, from Cornell University.
Eugene Veksler
Chief Financial Officer
A member of Emergent Medical Associates’ management team since 2019, Eugene Veksler has oversight responsibilities for the finance function. Prior to joining Emergent Medical Associates’ staff, Eugene held various financial positions within Eisner Health, StarPoint Properties, The Walt Disney Company, and The Clorox Company. He holds a BS degree in Business Administration from the University of Southern California. He is also an alumnus of the Health Care Executive Program at UCLA and has completed the Business Analytics Program at Harvard University.
David Jin
Chief Operating Officer
Responsible for leading and managing all aspects of analytical reporting, project management and corporate initiatives
• Previous experience in multi-national public and private organizations, leading financial operations on several continents
• B.A. in Business Economics from UC Santa Barbara, M.B.A. in Finance from University of Colorado, Boulder.
Nancy Garcia
Chief Administrative Officer
Responsible for overseeing daily administrative operations and human resource management
• Previous experience in business management specializing in the entertainment and apparel industry
• B.S. in Accounting, California State University, Northridge
Kristi Tucker
Chief Provider Relations Officer
Responsible for Recruiting, Credentialing and Scheduling
• First employee, helping the company grow from a single contract to its size today
• B.S. in Health Administration, University of Phoenix
Shweta Patel, Esq.
General Counsel
Responsible for managing and leading internal legal matters
• Prior experience within the medical/healthcare industry; medical malpractice defense; Assistant GC for a for-profit healthcare organization
• J.D. from Southwestern Law School / B.A. in International Studies with a focus on Business Management, University of California, Irvine
Lee R. Weiss, M.D., FACP, FACEP
Regional Medical Director – Los Angeles, Hawaii
Dr. Lee R. Weiss is currently Medical Director of Emergency Medical Services at Huntington Beach Hospital and Co-Medical Director of the Department of Emergency Medicine at Centinela Freeman Medical Center in Inglewood, CA.
A graduate of the State University of New York at Downstate School of Medicine, Dr. Weiss trained in Internal Medicine, Immunology, Infectious Diseases, and Emergency Medicine at SUNY Downstate, Kings County Hospital, the National Institutes of Health, SUNY Stony Brook, Bellevue Hospital, and the New York University Medical Center.
Dr. Weiss previously was the Director of Emergency Medical Services at Knox Community Hospital in Mount Vernon, OH, and most recently Vice Chairman of the Department of Emergency Medicine at St. Vincent’s Medical Center in Bridgeport, CT. Dr. Weiss previously held faculty positions in the Departments of Medicine and Emergency Medicine at New York University School of Medicine, The Bellevue Hospital Center, and The Ohio State University School of Medicine.
Dr. Weiss is the founder and previous managing partner of Synergy Micro Systems in Columbus, OH. For the past twenty plus years, Dr. Weiss has focused his research interests on the Epidemiology and Management of Outpatient Infectious Diseases. His major research focus has been the epidemiology of resistance in Streptococcus pneumonia.
An avid international traveler, for the past twenty years, Dr. Weiss has volunteered with Doctors without Borders in Africa and Central Asia. Dr. Weiss resides with his wife Dr. Michelle Weiss and son Gavin in Hermosa Beach, CA.
Jason Greenspan, M.D., FACEP
Regional Medical Director – SFV
Raised in Southern California, Dr. Jason Greenspan received his Bachelor’s degree from the University of California, Berkeley and his MD from the University of Southern California. He then completed his residency training in Emergency Medicine at LAC+USC Medical Center, where he was Chief Resident.
Kelly Unger, M.D.
Regional Medical Director – Orange County
Dr. Kelly Unger received her Bachelor’s degree at UCLA in physiologic science and medical degree from UCLA School of Medicine. She then completed an Emergency Medicine residency at the Jacobi Montefiore Program at Albert Einstein in the Bronx, NY.
She joined EMA upon moving back to Southern California in early 2008. She began administratively as Assistant Director at La Palma Intercommunity Hospital and Huntington Beach Hospital. She is currently the Regional Medical Director for Orange County as of July 2015 and has been the Medical Director for College Medical Center Long Beach since April 2014.
Pranav Kachhi, M.D.
Regional Medical Director - Riverside County
Dr. Pranav Kachhi grew up in the city of Los Angeles. He attended college at UCLA and is thereby a die hard Bruin for life! After college, he moved to Philadelphia where he attended Thomas Jefferson for medical school. He then pursued his interest in emergency medicine by attending residency at LAC/USC Medical Center. Upon completion of his residency in 2001, he joined EMA.
He has worked at multiple EMA sites and hospitals and prides himself in being able to function in a variety of emergency department settings. In 2013, he helped open a brand-new hospital, Temecula Valley, where he currently serves as the Medical Director of the Emergency Department. He currently lives in Northern San Diego and is happily married.
Jordan Cohen, M.D.
Regional Medical Director – San Diego County
Dr. Jordan Cohen was born in Israel, but raised in Southern California. He completed undergraduate studies at UC Irvine before attending medical school at UCLA. After a three year residency in emergency medicine at University of Illinois, Chicago, Dr. Cohen returned to California to direct the emergency medicine program at St. Mary's Medical Center, San Francisco as well as attending at various other Bay Area hospitals.
Prior to joining EMA in January 2012, Dr. Cohen also worked as ED attending in several hospitals in New Jersey. Dr. Cohen is currently the medical director of the ED at Alvarado Hospital as well as the regional director for San Diego county. He has held teaching positions at UCSF, UC Irvine and University of Illinois, Chicago.
Jose Diaz, M.D.
Regional Director – San Bernardino
Dr. Jose Diaz, a native of the South Bay, grew up in the city of Lomita. He completed his undergraduate studies at the University of California, Los Angeles, where he became an avid UCLA sports fan. Dr. Diaz pursued his medical education at the University of California, San Francisco, and completed his Emergency Medicine residency at Los Angeles County/USC Medical Center, now known as LA General Medical Center.
Dr. Diaz has been with EMA since 2000 and serves as the San Bernardino Regional Medical Director. In addition, he is the ER Medical Director at San Dimas Community Hospital and Chino Valley Medical Center, where he has held several medical staff administrative positions, including treasurer, Vice Chief of Staff, and Chief of Staff.
Alan Heilpern, M.D.
Medical Director – Los Alamos
Brian Ostick, M.D.
Medical Director – Valley Presbyterian
Bruce Friedberg, M.D.
Medical Director – Palomar Poway & Escondido
Jay Melton, M.D.
Medical Director – Centinela
Jordan Cohen, M.D.
Medical Director – Alvarado & Palomar Escondido
Jose J. Diaz, M.D.
Medical Director - Chino Valley & San Dimas
Kelly Unger, M.D.
Medical Director – College & Corona
Lee R. Weiss, M.D.
Medical Director – Maui & Lanai
Marco Hernandez, M.D.
Medical Director – West Henderson
Martin Carrillo, M.D.
Medical Director – Chino Valley & Montclair
Melanie Stanzer, D.O.
Medical Director - La Palma & College
Pranav Kachhi, M.D.
Medical Director - Temecula Valley
Eugene Park, M.D.
Medical Director – Hollywood Presbyterian
Nicholas Borm, M.D.
Medical Director – Sherman Oaks
Geoffrey Smith, M.D.
Medical Director - Encino
David Ngo, M.D.
Medical Director - Huntington Beach
James De la Torre, M.D.
Director of Clinical Practice Improvement
Molly Brady, M.D.
Director of Clinical Education & Informatics
Jay Melton, M.D.
Director of Advanced Practice Provider Academy
Melanie Stanzer, D.O.
Director of Reimbursement & Coding and Director of Compliance & Government Related Services
Michael Macias, M.D.
Director of Ultrasound
Paula Whiteman, M.D.
Director of Pediatric Emergency Medicine
Carlee Carranza, D.O.
Director of Wellness & Innovation
Eugene Park, M.D.
Director of Fellowship, Quality, & Leadership Development
Prince Raj
Director of Scribe Program
Natalie Shum, M.D.
Director of Patient Experience
Bobak Zonnoor, M.D.
Associate Director of Clinical Education & Informatics
