St John's Mercy Medical Group in St Peters is part of a Physician – governed group practice. The Doctors who are part or St John's Mercy are all Board-Certified and Board-Eligible. The 163 physicians and 30 nurse practitioners who make up St John's Mercy Medical Group emphasize wellness and offer preventative medicine as well as treating existing conditions. The organization has one of the largest groups of general Pediatricians in the region. If unable to offer you the treatment you need, St John's know where you can get it and will help get you reffered.