About This Location
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Edwin T. Castañeda, MD
Edwin T. Castañeda MD, FACP, is a graduate of St. Louis University Medical School and trained at Hackensack University Medical Center in New Jersey. He is a Fellow of the American College of Physicians and a Diplomat of the American Board of Internal Medicine. Dr. Castañeda is also a member of the American Association for Physician Leadership. He is an adjunct clinical instructor for the University of Maryland Medical School. He was a former Hospitalist at AGH and Memorial Hospital in Easton, MD. He served as Chief of the AGH Medical Staff from 2006-2009. He served as Chief of the AGH Department of Medicine from 2001-2003. He has held numerous AGH medical staff leadership roles. He served as a member of the AGH Board of Trustees from 2013-2019. He has been serving our community and AGH as an Internist over the last 26 years. He is currently an Internal Medicine specialist with AGHS in Berlin, Maryland. He lives in Ocean Pines, Maryland, with his wife, Jessie. His children, Christian (Pulmonologist /Critical Care specialist) and Gaby (Psychologist), reside in New York City. Dr. Castañeda has run the NYC Marathon and participated in the Seagull Century Bike Tours numerous times.
Alison Diesel, PA-C
Alison Diesel is a physician assistant at Atlantic General Internal Medicine, in Berlin, Maryland. Raised in Worcester County, Alison is a graduate of Stephen Decatur High School. She earned her Bachelor of Science in Biology from Towson University, where she played Division I lacrosse, before attending Keiser University in Fort Lauderdale, Florida, for her Master of Science in physician assistant studies. Alison returned to the Eastern Shore in 2015 to begin caring for patients in her community. Alison provides primary care to adult patients alongside internist Edwin Castaneda, MD. She is certified by the National Commission on Certification of Physician Assistants.
Mary Mason, DNP
Mary Mason, DNP, CRNP, FNPBC, joined Atlantic General Health System in 2024 to help expand access to primary care services in Berlin, Maryland, and surrounding communities.
Mary earned her Bachelor of Science in Nursing from the University of Memphis and spent the next 10 years gaining experience as a registered nurse and a preceptor to nursing students in various care settings.
Her passion for providing quality care led her to continue her education, and in 2024, she earned a Doctorate in Nursing Practice-Family Nurse Practitioner degree from the University of Tennessee at Knoxville. Mary is board certified by the American Nurses Credentialing Center, and she is a member of the American Association of Nurse Practitioners.
She is currently accepting new patients, and appointments can be scheduled by calling 410-629-0041.