York Hospital is pleased to announce the arrival of the following providers to its medical staff in early 2022. Jill DiMartinis, MD and Michael Ross, DO have joined York Hospital Family Medicine in Wells and Jenna Lizewski, DNP, FNP-C comes to York Hospital Family Practice in Sanford. William Kiley, Jr., DO will be joining the team at Surgery Associates of York Hospital on the York Campus, while Brandon Rivard, PA is seeing patients at The Center for Older Adult Care in South Berwick. Ashley Webster, FNP-BC will be caring for patients at Pediatric Associates of York Hospital in Wells.


Jill DiMartinis, MD, joins her colleagues at Family Medicine in Wells, after holding family medicine positions at Scarborough Integrative Health in Scarborough, ME, Southern Maine Health Care in Saco, InterMed in Yarmouth and serving as general medical officer at Mayport Naval Station in Florida. Dr. DiMartinis earned her BA at University of Virginia, and MD at Tufts University School of Medicine. Following an internship at the Naval Hospital in Jacksonville, FL she completed her residency in Family Medicine at University of Massachusetts in Worcester, MA. Dr. DiMartinis recognizes the significant change in medicine right now, and “hopes to provide a friendly face to the community, a physician that patients can rely on to provide compassionate care as we navigate the challenges of the current environment.” When not caring for her patients you may find her outdoors enjoying her garden or picking up a racquet or, depending on the season, indoors cooking, reading, and enjoying time with her two high school age children.


William Kiley, Jr., DO, FACOS, FACS, joins the staff at Surgery Associates of York Hospital at the end of January. Dr. Kiley earned his BA at Saint Anselm College in Manchester, NH and DO at Kansas City University of Medicine and Biosciences in Kansas City, MO. Following an internship at Community General Osteopathic Hospital in Harrisburg, PA he completed his surgical residency at both Mercy Catholic Medical Center in Darb and Mercy Suburban Hospital in Norristown, where he was chief surgical resident. Dr. Kiley’s experience has brought him to various health care organizations throughout Maine and Southern New Hampshire, including Rumford Hospital in Rumford, Southern Maine Medical Center in Biddeford, Goodall Hospital in Sanford, Parkview Adventist Medical Center in Brunswick, Bridgton Hospital, and Frisbie Hospital in Rochester, NH. His interests beyond the OR suite include scouting, aviation, history, golf and spending time with his family.


Jenna Lizewski, DNP, FNP-C, is excited to become the newest provider at York Hospital Family Practice in Sanford. She earned her BSN from Salve Regina University in Newport, RI, followed by a Master of Science Family Nurse Practitioner degree, and Doctor of Nursing Practice degree, both from the University of Massachusetts Medical School Graduate School of Nursing. Ms. Lizewski’s earlier nursing years were spent caring for patients in both mental health and emergency department settings, while her more recent experience has been as a nurse practitioner in pre-surgical evaluation, primary care and workplace-based health. She is passionate about preventative care and health education, has enjoyed mentoring nurse practitioner students, and participated for many years as a member of the American Lung Association Massachusetts Leadership Board. When not caring for patients, you’ll find her biking, hiking and at the beach with her husband, two children and loyal dog.


Brandon Rivard, PA-C, is now seeing patients at York Hospital’s Center for Older Adult Care in South Berwick. Mr. Rivard earned his BS in Biology with a minor in Psychology from Northeastern University in Boston, MA, followed by an MS in Physician Assistant Studies from South University in Richmond, VA. His professional experience has included serving at the Center for Advanced Orthopaedics Studies at Beth Israel Deaconess Medical Center and Boston University Emergency Medical Services, Harvard Vanguard Medical Associates in Wellesley, MA, and Tapestry Healthcare in Sanford and Berwick, where he provided on-site and telehealth medical services to long term care residents. His hope is to help his patients reach their short and long-term health care goals while enjoying a healthy and satisfying life. An avid sports fan, you’ll find him cheering on the Bruins and Patriots on game days, joined by Dylan, his labrador mix, along with his new Bernese mountain dog puppy.


Michael Ross, DO, will join his colleagues at York Hospital Family Medicine in Wells, welcoming the opportunity to develop trusting relationships as cares for his patients throughout their lives. Dr. Ross has an extensive background in both geriatrics and primary care, including geriatrician for the Program of All-Inclusive Care for Elders (PACE) in Rhode Island, Director of Inpatient Geriatric Medicine and Director of Education, Division of Geriatrics & Palliative Care at Kent Hospital/Care New England, and his most recent post as Medical Director of Primary Care, Health @ Home with Neighborhood Health Plan of Rhode Island. He earned his BS in Health Studies from Boston University, followed by a DO from the University of New England College of Osteopathic Medicine.  Dr. Ross completed his residency at New Hampshire Dartmouth Family Medicine, along with a fellowship at Maine Dartmouth Geriatric Medicine in Augusta, ME and Brookdale Dept. of Geriatrics & Palliative Medicine at Mount Sinai School of Medicine in New York, NY. He has also held the position of Assistant Professor of Medicine, Clinical Educator at The Warren Alpert Medical School of Brown University in Providence. Dr. Ross’s life outside of the office revolves around family, friends and a cairn terrier named Simon. You may find them hiking, running, paddleboarding, and at this time of year, putting on snowshoes and cross-country skis for some fresh air.


Ashley Webster, FNP-BC, will join the team at Pediatric Associates of York Hospital in Wells, caring for patients from birth through young adulthood. Ms. Webster began her nursing career in the Special Procedures Department at York Hospital and is excited to return to York as a Nurse Practitioner at Pediatrics Associates. She has worked in the Cardiac ICU at Elliot Hospital, Manchester, NH and the Intravascular Cardiac ICU at Portsmouth Regional Hospital, where she often performed duties of charge nurse and nurse leader, with a focus on quality care and patient safety. She earned a BSN, RN at Saint Joseph’s College in Standish, ME, followed by her MSN, FNP-BC at the University of New Hampshire in Durham. She looks forward to advocating for young patients’ well-being, while providing compassionate, safe and evidence-based care that empowers family wellness. When away from the office, Ms. Webster enjoys running and hiking, and she and her husband are kept on their toes by two young boys with endless energy and a fondness for chasing crabs on the beach.


For more information about these newest members of the York Hospital medical staff, please call York Hospital at 207-351-2273. For further details about other York Hospital providers and services, visit or contact Community Relations at 207 351-2385 or [email protected].