Gary Hammer, MD
NPI 1871676791 · Endocrinology, Diabetes & Metabolism Physician · Ann Arbor, MI
Enrolled with Medicare as Practitioner - Endocrinology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gary Hammer, MD is a Endocrinology, Diabetes & Metabolism Physician provider in Ann Arbor, MI (NPI 1871676791).
Provider details
- NPI number
- 1871676791
- Entity type
- Individual
- Primary specialty
- Endocrinology, Diabetes & Metabolism PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 4301075475 (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 tenure33% of score
19 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
2 documented practice locations
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Hydrocortisone | 25 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$5,000 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (1)
- 1500 East Medical Center Dr1st Floor Cancer & Geriatrics CenterAnn Arbor, MI 48109-5354Phone: (734) 763-4876
Registry dates
- Enumerated
- 2006-10-23
- Last updated
- 2025-10-02
- Certified
- 2025-10-02
Frequently asked questions
- What is Gary Hammer's NPI number?
- Gary Hammer's National Provider Identifier (NPI) is 1871676791, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gary Hammer's specialty?
- Gary Hammer is listed in the NPPES registry with a primary specialty of Endocrinology, Diabetes & Metabolism Physician (Allopathic & Osteopathic Physicians).
- Where is Gary Hammer located?
- Gary Hammer's practice location on file with NPPES is 1500 E Medical Center Dr, Ann Arbor, MI 48109-5000.
- What is Gary Hammer's phone number?
- The practice phone number listed in the NPPES registry for Gary Hammer is (734) 936-4000.
- Does Gary Hammer accept Medicare?
- Gary Hammer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gary Hammer's NPI active?
- Yes — Gary Hammer's NPI (1871676791) is active in the NPPES registry as of the last update on 2025-10-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.