Our Providers

Background: Dr. David A. McCarthy founded the practice in 1998 after 24 years of service in the Air Force Medical Corps. He also was an assistant professor at a University Family Practice Residency. He and his family have lived in O'Fallon since 1993.

Background: PA Robert Dizes joined the practice in 1999. He served in the Medical Corps of the United States Air Force and retired after 20 years of service. He holds a masters degree in Family Medicine. Some of his achievements include: Clinical instructing for both military and civilian physician assistant teaching programs.

Background: PA Marc Boyer joined the practice in the summer of 2004. He is retired from the US Air Force after serving 21 years in the medical field. He has worked in Primary Care, Family Practice, Emergency Room, and Internal Medicine. His greatest achievement was his three years of service on the President's traveling medicine team at the White House. PA Boyer and his family live in the Belleville area.

Background: Dr. Donald Clark was born and raised in the Midwest and formerly practiced out of Winter Haven, Florida. He and his family are very excited to be back in the Midwest. Dr. Clark went to medical school at Michigan State University and did his Residency with the University of Missouri, Kansas City. He is a member of the American Academy of Family Physicians. He is married and has two children.

Background: Dr. Scott Morrison is an O'Fallon native who formerly practiced out of Pekin, Illinois. He and his wife Robin are excited to have returned to the O'Fallon area. He went to medical school at Saint Louis University School of Medicine and did his residency at Methodist Hospital in Indianapolis, Indiana. Dr. Morrison served several years in the Air Force prior to returning to civilian practice. He is a member of the American Academy of Family Physicians, the Illinois Academy of Family Physicians, and the Wilderness Medical Society.

Background:Dr. Donna Wagstaff is originally from the Southern Illinois region. She spent several years as an Army Physician and is happy to return to this area. She went to medical school at St. Louis University and did her residency with Womack Army Medical Center. She is a member of the American Academy of Family Physicians.

Background:Dr. Craig Lotz is a Kentucky native who joined the practice in September 2009. He received his Master’s degree from Spalding University in 2004 and completed his Doctorate degree in Clinical Psychology with an emphasis in Children, Adolescents, and Families in 2007. Dr. Lotz completed his pre-doctoral training at Father Flanagan’s Girls and Boys Town in Omaha, Nebraska. He is a member of the American Psychological Association and the Illinois Psychological Association. Dr Lotz and his wife live in the O’Fallon area.

Background: PA Tina Diekemper joined the practice in December 2009. She is a native of southern Illinois and has been practicing Family Medicine for 10 years. PA Diekemper is a graduate of Midwestern University and is a member of the AAPA.