William Gretzinger, DO
NPI 1518994979 · Emergency Medical Services (Emergency Medicine) Physician · Petoskey, MI
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Gretzinger, DO is a Emergency Medical Services (Emergency Medicine) Physician provider in Petoskey, MI (NPI 1518994979).
Provider details
- NPI number
- 1518994979
- Entity type
- Individual
- Primary specialty
- Emergency Medical Services (Emergency Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Male
- Sole proprietor
- No
- License
- 5101011330 (MI)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-06-28
- Last updated
- 2019-10-09
Frequently asked questions
- What is William Gretzinger's NPI number?
- William Gretzinger's National Provider Identifier (NPI) is 1518994979, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Gretzinger's specialty?
- William Gretzinger is listed in the NPPES registry with a primary specialty of Emergency Medical Services (Emergency Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is William Gretzinger located?
- William Gretzinger's practice location on file with NPPES is 416 Connable Ave, Petoskey, MI 49770.
- What is William Gretzinger's phone number?
- The practice phone number listed in the NPPES registry for William Gretzinger is (231) 487-4000.
- Does William Gretzinger accept Medicare?
- William Gretzinger is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Gretzinger's NPI active?
- Yes — William Gretzinger's NPI (1518994979) is active in the NPPES registry as of the last update on 2019-10-09.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.