Dr McSwain and his wife Teresa moved to Skaneateles in 2003 and he has been in private internal medicine and pediatrics practice since that time. He has 4 daughters who have attended Skaneateles Central Schools to include his oldest who graduated in 2020. He received his BS from Virginia Military Institute where he graduated 1st in his class. He then attended Duke University School of Medicine where he graduated in 1994. He completed a 4-year residency program in Pediatrics and Internal Medicine from University of Rochester in Rochester, NY. He did serve as a Captain in the Army Reserves Medical Corps. More recently he founded the Urgent Care of Auburn and served as its medical director until 2020. He is also the occupational medicine director for Auburn Hospital.

Mark has previously served as the chairman of the department of family practice at Auburn Community Hospital and on the executive committee of the hospital. He has also served on the board for Holy Trinity Preschool and has been a soccer coach for Skaneateles Youth Soccer.