GARY DOUGLAS HAMMER MD
NPI 1871676791
Internal Medicine - Endocrinology, Diabetes & Metabolism in Ann Arbor, MI
About Gary Douglas Hammer Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
GARY DOUGLAS HAMMER MD (NPI 1871676791) is an individual endocrinology, diabetes & metabolism provider in Ann Arbor, Michigan, licensed in Michigan (4301075475) and active in the NPI registry since October 2006. He is enrolled in Medicare PECOS, is affiliated with University Of Michigan Health System, and maintains a secondary practice location in Ann Arbor.
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Other Identifiers 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Gary Douglas Hammer Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
University Of Michigan Health System
Acute Care Hospitals · Ann Arbor, MIPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 48109 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
ANN ARBOR, MI 48109
ANN ARBOR, MI 48109
ANN ARBOR, MI 48109
ANN ARBOR, MI 48109
ANN ARBOR, MI 48109
ANN ARBOR, MI 48109
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Gary Hammer's NPI number?
The NPI number for Gary Hammer is 1871676791. It was assigned to this individual provider in the NPPES registry on October 23, 2006.
Where is Gary Hammer located?
Gary Hammer practices at 1500 E Medical Center Dr, Ann Arbor, MI 48109. The listed phone number is (734) 936-4000.
What is Gary Hammer's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Endocrinology, Diabetes & Metabolism, with taxonomy code 207RE0101X.
Is Gary Hammer enrolled in Medicare?
Yes. Gary Hammer is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
What insurance does Gary Hammer accept?
Health plans from Ambetter Health, Ambetter from Buckeye Health Plan, Ambetter from Meridian, Blue Care Network of Michigan and Blue Cross Blue Shield of Michigan Mutual Insurance Company and 2 other insurers list Gary Hammer as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Gary Hammer affiliated with any hospitals?
According to CMS data, Gary Hammer is affiliated with University Of Michigan Health System.
When was this NPI record last updated?
The NPPES record for Gary Hammer was last updated on October 2, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Gary Douglas Hammer, MD · NPI 1871676791
Endocrinology, Diabetes & Metabolism physician in Ann Arbor, Michigan. Individual provider, active in the CMS NPPES registry since October 23, 2006.
## Identity
- **NPI:** 1871676791 (Entity type: Individual)
- **Enumerated:** October 23, 2006
- **Primary specialty:** Internal Medicine - Endocrinology, Diabetes & Metabolism · taxonomy 207RE0101X
- **State license:** 4301075475 (Michigan)
- **Sole proprietor:** No
## Practice location
- **Address:** 1500 E MEDICAL CENTER DR, Ann Arbor, MI 48109-5000
- **Phone:** (734) 936-4000
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Medical school:** Tufts University School Of Medicine, class of 1992
## Record status
- **NPPES last updated:** October 2, 2025
- **Other identifiers:** Medicaid 4177663 (MI)
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Source: [NPI Profile](https://npiprofile.com/npi/1871676791) · Data from the CMS NPPES public registry.