
Andrew T. McMahon, MBA
Executive Director
Andrew McMahon comes to UHS with two decades of operations, finance and leadership experience in healthcare and government entities.
He most recently served as the Associate Director of Operations in the Veterans Health Administration, overseeing all operations for the regional healthcare system. During his tenure, Andrew was recognized for outstanding financial stewardship and modernizing the infrastructure of the regional assets. Andrew served as the interim CEO of the system for nearly a year through many challenging undertakings, including the initial months of the pandemic, while safely guiding the delivery of healthcare and meeting the needs of the patient population. Prior to becoming the Associate Director, Andrew was the Chief Financial Officer of the organization, overseeing an annual budget in excess of $300M locally, and was a key part of the team coordinating the $1.5B northeastern budget. While CFO, in 2014 Andrew was recognized by BusinessWest as one of their 40 Under 40.
Andrew holds a B.S. in Management from the University of Maryland, and an M.B.A. from Boston University with a Graduate Certificate in Project Management. Andrew has graduated from numerous leadership and technical schools to include the VA Healthcare Leadership Development Program, OPM Senior Executive Service Assessment Program, Officer Training School, Comptroller School, Squadron Officer School and the Budget Officer course. He holds a Department of Defense Level II Finance Certification and is a Certified Government Financial Manager.
Andrew is a U.S. Air Force Veteran, and he continues to serve part time as a Budget Officer. He volunteers on local boards in his hometown of Holyoke, MA and serves on the Board of Directors for the Red Cross of Western Massachusetts. When not working, Andrew is kept busy by his active high-school-aged son.

Ivan E. Correa, MD, CMD
Medical Director
Dr. Ivan Correa is board certified in family and geriatric medicine. Prior to joining University Health Services, he served as Chief of Staff for the VA Central Western Massachusetts Health Care System and the Atlanta VA Health Care System. In these roles, he oversaw vast integrated healthcare systems focused on research, teaching, ambulatory care, and surgical units, as well as significant behavioral health operations.
He has had academic appointments as Geriatric and Hospice and Palliative Medicine Clinical Assistant Professor at Emory University, the University of Nevada Reno School of Medicine, and University of New Mexico School of Medicine.
His leadership style is characterized by an emphasis on relationship-building, attentive listening, and collaborative approaches. Dr. Correa's journey began as a research microbiologist, contributing to the US Environmental Protection Agency and the Department of Defense before embarking on his medical career.
He holds a bachelor’s degree of science from the University of Puerto Rico, started medical school at the Universidad Autónoma de Guadalajara, and finished his medical education at New York Medical College in Valhalla, New York. He completed his graduate medical education at the Advent Health System in Orlando Florida (formerly Florida Hospital Orlando).
Dr. Correa’s research and medical interests include caregiver burden in dementia, symptom management in Amyotrophic Lateral Sclerosis (ALS), end-of-life care, and prevention of polypharmacy in the elderly.

Khama Ennis, MD, MPH, FACEP
Assistant Medical Director of Walk-In Clinic
Dr. Khama Ennis brings a wealth of experience in emergency medicine, integrative medicine and health equity to UHS. Her background includes leading efforts to stabilize and grow provider groups and enhance patient flow through changing processes and improving electronic health record systems. Her work as a health equity advocate, including published essays in the Washington Post and a documentary project, Faces of Medicine, exploring the paths of Black female physicians in the United States, underscores her dedication to addressing disparities in healthcare.
Prior to joining UHS, Dr. Ennis served as chief & medical director of emergency medicine at Cooley Dickinson Hospital in Northampton, MA, and also completed a two-year term as President of the Medical Staff. She earned her Medical Doctorate at New York University School of Medicine, her Master’s in Public Health at Harvard T.H. Chan School of Public Health, and her Bachelor of Arts in Medical Anthropology at Brown University. She completed residencies at Mass General Hospital and Brigham & Women’s Hospital in Boston, MA. Dr. Ennis is board certified in emergency medicine and holds a certificate in physician acupuncture. She has completed fellowship training in Integrative Medicine.
In her new role at the UHS Walk-In Clinic, Dr. Ennis will utilize her extensive leadership experience and passion for holistic care to further enhance the quality and accessibility of the services UHS provides. Her innovative approach and commitment to excellence will be instrumental in supporting UHS’s mission to provide comprehensive and compassionate care to the UMass community.

Leora Cohen-McKeon, DO
Associate Medical Director of General Medicine and Sexual and Reproductive Health Clinics
Dr. Leora Cohen-McKeon oversees the clinical aspects of day-to-day operations in the general medicine and Sexual & Reproductive Health clinics, ensuring that services are delivered smoothly and effectively. She leads quality improvement initiatives focused on enhancing patient care quality and safety, identifying areas for improvement, and implementing evidence-based practices, helping UHS continue to achieve excellence in healthcare.
Dr. Cohen-McKeon has been a valued member of the UHS team since 2017, bringing a wealth of knowledge and experience to her practice. Her medical interests are rooted in primary care and family medicine, with expertise in addiction medicine, women’s health, transgender health, and eating disorders. Her educational background includes a Doctor of Osteopathy degree from the University of New England College of Osteopathic Medicine in Biddeford, Maine, and a Bachelor of Arts from Swarthmore College in Pennsylvania. She completed her residency with a concentration in women’s health at Swedish Family Medicine at Cherry Hill in Seattle, Washington.
Her professional journey prior to joining UHS has been diverse and impactful, having served as a family physician at Martin’s Point Health Care in Portland, Maine. Locally, she was a family physician at Holyoke Health Center and a senior family assessment worker at Ulster County Healthy Start in New York.
Dr. Cohen-McKeon is board certified by the American Board of Family Medicine and holds additional certifications as a buprenorphine prescriber and in colposcopy. Her commitment to providing comprehensive, compassionate care is evident in every aspect of her work.
Cheryl Sherry
Practice Manager
Cheryl Sherry serves as the Practice Manager at University Health Services, a role she has embraced since May 2023. At the core of her responsibilities lies a meticulous approach to managing and overseeing clinical workflows, coupled with an unwavering commitment to being a staunch patient advocate. Cheryl's career spans over thirty years in health-related fields, marked by her certification as a medical assistant by the American Association of Medical Assistants and numerous certifications in clinical and office management. In addition to her managerial role, she is the proud owner of a business specializing in First Aid and CPR instruction and certification, a testament to her dedication to promoting health and safety.
Cheryl's journey at University Health Services began as a medical assistant in urgent care and the clinics, laying the foundation for her comprehensive understanding of various service areas. Prior to assuming the role of Practice Manager, she excelled as the Referrals, Registration, and Reception Manager, showcasing a keen focus on directing patient referrals and elevating the standard of clinical reception across multiple practice sites and specialty clinics. Each career milestone has fueled her passion for clinical practice and strengthened her commitment to patient advocacy.
Beyond her professional achievements, Cheryl finds fulfillment in her personal life. Nestled in the vibrant community of Amherst with her husband Paul, she has successfully raised two daughters and delights in her role as the proud Nana to a grandson. Cheryl's multifaceted experience, technical expertise, and unwavering dedication to ongoing education make her an invaluable asset in the dynamic landscape of healthcare.