The leaders behind it all.

Meet The Team

Executive Leadership


Etan Walls

Chief Executive Officer

Chief Executive Officer of Adjuvant.Health. Currently Etan, is the Chief Operating Officer for Allied Physicians Group, a premier primary care independent physician group with over 30 locations throughout the New York metropolitan area, as well as, Board Member of the Allied Foundation. In his professional role, Etan is responsible for the internal coordination and implementation of the Allied strategic organizational vision by guiding and leading the internal teams. With over 20 years of technology and project management solutions experience, over15 within Healthcare, Etan has extensive knowledge of Healthcare policies, procedures and workflows as it relates to ambulatory care.


As past President of the Centricity Healthcare User Group (CHUG), Etan has been able to expand his reach to a larger audience through speaking engagements and executive level discussion. Etan has been very involved early stage Healthcare IT startups as a mentor or as a sitting advisory board member.


Robert Creaven

Chief Operating Officer

Robert has over 24 years of experience working within Healthcare Administration. Currently, Robert works as Allied Physicians Group’s Executive VP of Operations, managing divisional profits, RCM and analytics for 150+ providers.


Previously, Robert was the VP of Business Development for Allied Physicians Group and Director of Business Development for NRAD Medical Associates, where he increased Physician Partnerships and Specialties.


Valerie Mayer

Chief Financial Officer

Valerie is a talented and seasoned executive with over 20 years of experience in financial planning and operations in multiple verticals including healthcare, manufacturing, and construction. She brings a wealth of expertise with particular strengths in areas such as financial reporting, internal controls, and both financial strategy and long-term budgetary oversight.  She obtained her MBA from Hofstra University and her CPA designation.  Valerie was recently awarded by LIBN, One of the 50 Top Women in Business.


Ricardo Santiago

Chief Information Officer

Ric is a creative, seasoned Healthcare Technology Professional with twenty-three years of experience in diverse healthcare management settings, including hospital, long term care, home health care and various ambulatory environments.  As Chief Information Officer, Ric has provided Technology vision and leadership for the continued development of innovative, robust and secure environments.


With focuses on Governance, Security and Service Delivery, Ric has been able to align business priorities with technology strategy delivering transformative outcomes.


Prior to joining ‘Allied/Adjuvant’, Ric served as Chief Information Officer for Village Care of New York.  In his role, he leveraged new technologies and interdepartmental relationships to foster increased quality care enhancing the organizational mission.


Megan Millevoy

Chief People Officer

Megan Millevoy is the Vice President of Human Resources at Allied Physicians Group, one of the largest private medical partnerships in the New York, Metropolitan area. With over 15 years of HR experience, Megan has spent most of her career in implementations, mergers and acquisitions and consolidation of multiple plans and business lines into one. During her tenure at Allied, she has worked to centralize the Human Resources function from 35 independent practices down to a single, cohesive model.


Leslie Tarver

Vice President of Patient Experience & Marketing

Leslie has over 17 years’ experience in Healthcare and management. Her expertise is in culture, marketing, practice management, teaching, technology, and workflow/process improvement. She is trained in LEAN for healthcare and speaks more than twice a year at healthcare conferences. Leslie also sits on GE’s advisory board for their practice management and EMR solutions.

Physician Leadership


Kerry Fierstein

CEO, Allied Physicians Group & Executive Board Member, Adjuvant.Health

Born in the Bronx and raised in Queens, Dr. Kerry Frommer Fierstein is a New Yorker all the way. Flushing High School led to New York University, which led to New York Medical College where she met her husband David, the internist. Her residency was completed at North Shore University Hospital – Manhasset, and she has been a Long Island pediatrician since 1990. She is a practicing partner at Pediatric Health Associates in Plainview, New York.  Dr. Kerry Fierstein serves as the Chief Executive Officer of Allied Physicians Group.


Jennifer Shaer

CMO, Allied Physicians Group

Dr. Shaer is a graduate of Mount Sinai School of Medicine. She completed her pediatrics residency at Albert Einstein/ Montefiore Medical Center and was chief resident at Jacobi Medical Center. Dr. Shaer is a board-certified pediatrician, an International Board Certified Lactation Consultant and a fellow of the Academy of Breastfeeding Medicine. She is a practicing partner at Peconic Pediatrics in Riverhead & Southold, New York. Dr. Shaer also serves as the Chief Medical Officer at Allied Physicians Group.


Gary Mirkin

President, Allied Physicians Group & Board Member, Adjuvant.Health

Dr. Gary Mirkin, a founding member of Allied Physicians Group, graduated from The Ohio State University with a B.S. in Microbiology in 1979. He then went on to The Ohio State University College of Medicine, which he completed in 3 years, graduating in 1982. Dr. Mirkin completed his residency in Pediatrics at The New York Hospital-Cornell University Medical Center from 1982-1985. He has been board certified in Pediatrics since 1989, is a fellow of the American Academy of Pediatrics, and has a special interest in dealing with infectious disease and autism. He has been honored with the Healthcare Heroes Physician Hero Award in 2013 as well as a “Top CEO” in 2016 by Long Island Business News.  Dr. Mirkin serves as the President of Allied Physicians Group and is a practicing partner at MDs4Kids in Great Neck, New York.


Clare Cohen

Treasurer, Allied Physicians Group & Board Member, Adjuvant.Health

Dr. Cohen was born and raised in New York. She received her bachelor’s degree from Binghamton University and then went on to receive her medical degree from SUNY Syracuse. She completed her pediatric residency at North Shore University Hospital in Manhasset. She has enjoyed caring for the Garden City Pediatric community for the past 20 years. Dr. Cohen serves as the Allied Physicians Group Treasurer.


Stewart Samuel

IT Steering Committee Chair, Allied Physicians Group

Born and raised in Kentucky, Dr. Stewart Samuel graduated from Indiana University and the University of Louisville School of Medicine. He completed his pediatric training at the Children’s Hospital Medical Center in Cincinnati and then spent four years in the US Army at FT Knox where he served as Chief of Pediatrics, Medical Director for the Early Intervention Program, and coordinator of services for child abuse victims. Dr. Samuel is a practicing partner at Pediatric Health Associates in Plainview, New York. He also serves as Chairperson of the IT Steering Committee for Allied Physicians Group.


Scott Svitek

Human Resources Committee Chair, Allied Physicians Group

Dr. Scott Svitek received his Bachelor of Science in Molecular Genetics at the University of Rochester and Medical degree at the University of Buffalo. He completed his pediatric training at LIJ medical center and then served as the Senior Chief Resident. But after serving several years than an academic setting at the Schneider’s Children’s Hospital t LIJ, Dr. Svitek returned home and has been at Commack Pediatric Associated since 1998. Dr. Svitek serves as the Human Resources Committee chair for Allied Physicians Group.


Brad Fell

Compliance Officer, Allied Physicians Group

Dr. Fell is a graduate of The Sophie Davis School of Biomedical Education and SUNY Health Science Center in Syracuse. He completed his Internship and Residency at Steven and Alexandra Cohen Children’s Medical Center (formerly Schneider Children’s Hospital), where he also served as Chief Resident. He is a board-certified pediatrician and is an Associate Professor of Pediatrics at Albert Einstein College of Medicine and Hofstra Medical School. Dr. Fell is a practicing partner at Peconic Pediatrics in Riverhead & Southold, New York. He was a founding member of Allied Physicians Group, where he has been the company’s Compliance Officer and Privacy Officer, as well as the Billing and Coding Chairman.


Eric Levene

Marketing Committee Chair, Allied Physicians Group

Dr. Eric Levene joined Chester Pediatrics in 1993. Dr. Levene grew up on Long Island. He obtained his undergraduate degree in Mathematics from Franklin and Marshall College and received his medical degree from the University of Pittsburgh School of Medicine. He completed his residency at Long Island Jewish Hospital where he then continued for one more year as Chief Resident. Dr. Levene serves as the Allied Physicians Group Marketing Committee Chair.