HealthCareAtlasUSA

This site republishes official CMS/Medicare Care Compare data. It is not medical advice and does not recommend any specific hospital or treatment — for medical decisions, talk to a doctor.

Doctors / OH

GREGORY ROSS JOHNSTON, DO

GENERAL SURGERY

Medical school: MICHIGAN STATE UNIVERSITY COLLEGE OF OSTEOPATHIC MEDICINE

Graduated: 2008

NPI: 1982866109

Practice Locations (2)

MERCY MEDICAL PARTNERS NORTHERN REGION SPECIALTY CARE LLC

1400 E 2ND ST

DEFIANCE, OH 435122440

4197841414

MERCY HEALTH PHYSICIANS NORTH SPECIALTY CARE LLC

27 ST LAWRENCE DR, SUITE 201A

TIFFIN, OH 448838314

4194558500

Source: CMS National Downloadable File, September 2026.