Dr. Kollmann received his Bachelor of Science degree from Southern Illinois University in Carbondale, Illinois. He received his Doctor of Dental Medicine (DMD) from Southern Illinois University School of Dental Medicine in Alton, Illinois. Dr. Kollmann received his certificate in Pediatric Dentistry at the Children's Medical Center in Dayton, Ohio.

Dr. Kollmann has been in private practice since 1986. He is a member of the American Academy of Pediatric Dentistry, American Dental Association, Illinois State Dental Society, the Illilnois Society of Pediatric Dentistry, and the Madison District Dental Society, of which he served as president, president-elect and secretary. He is on staff at both Memorial Hospital in Belleville, Illinois and Anderson Hospital in Maryville, Illinois.

Dr. Kollmann lives in Collinsville with his wife Sherry. They have been married over 24 years and have one daughter, Kaitlyn.