Gary Douglas Hammer, MD

Primary specialty

Endocrinology, Diabetes & Metabolism PhysicianTaxonomy code 207RE0101X

License

4301075475 Issued in MI

Practice address

1500 E Medical Center Dr
Ann Arbor, MI 48109-5000

Phone

(734) 936-4000

NPI assigned

Oct 23, 2006

Sex

Male

Sole proprietor

No

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 2

Addresses

Other identifiers 1

Medicare fee-for-service enrollment

Enrolled in MI

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 1

Specialty

EndocrinologyAlso: Internal Medicine

Education

Tufts University School of Medicine, 1992

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Regents of the University of MichiganGroup PAC ID 3779496856, 3,344 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• University of Michigan Health System Hospital, Ann Arbor, MI, CCN 230046

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

• Regents of the University of Michigan

  • Internal Medicine Physician
  • Ann Arbor, MI
  • NPI 1205868353
  Medicare reassignment Care Compare group NPD
• Regents of the University of Michigan

  • Specialty Pharmacy
  • Dexter, MI
  • NPI 1952181919
  NPD
• Regents of the University of Michigan

  • Endocrinology, Diabetes & Metabolism Physician
  • Ann Arbor, MI
  • NPI 1962432963
  NPD
• Regents of the University of Michigan

  • General Acute Care Hospital
  • Ann Arbor, MI
  • NPI 1003878539
  NPD (past)
• Frederick Health Hospital Inc

  • General Acute Care Hospital
  • Frederick, MD
  • NPI 1538165527
  NPD (past)

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

• Regents of the University of Michigan

  • General Acute Care Hospital
  • Ann Arbor, MI
  • NPI 1003878539
  Care Compare affiliation

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1161561600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1759363200000",
    "number": "1871676791",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "3621 S STATE ST",
            "city": "ANN ARBOR",
            "state": "MI",
            "postal_code": "481081633",
            "telephone_number": "734-647-5299"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1500 E MEDICAL CENTER DR",
            "city": "ANN ARBOR",
            "state": "MI",
            "postal_code": "481095000",
            "telephone_number": "734-936-4000"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "1500 East Medical Center Dr",
            "address_2": "1st floor Cancer & Geriatrics Center",
            "address_purpose": "LOCATION",
            "city": "Ann Arbor",
            "state": "MI",
            "postal_code": "481095354",
            "country_code": "US",
            "telephone_number": "734-763-4876",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "HAMMER",
        "first_name": "GARY",
        "middle_name": "DOUGLAS",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-10-23",
        "last_updated": "2025-10-02",
        "certification_date": "2025-10-02",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RC0000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Cardiovascular Disease",
            "state": "MI",
            "license": "4301075475",
            "primary": false
        },
        {
            "code": "207RE0101X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Endocrinology, Diabetes & Metabolism",
            "state": "MI",
            "license": "4301075475",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "4177663",
            "state": "MI"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Mansurul Hamja
• Kristen Hamlin, OTR/L, CHT
• Shannon Elizabeth Hamlin, MSW
• Daeja Hamm
• Carl Hammaker
• Yoav Hammer, MD
• Brittany Anne Hammond, D.O.
• Kurt R Hammond, PHARM D
• Heather Hammons, PA-C
• Amny Hammoud

• Endocrinology, Diabetes & Metabolism Physician in Ann Arbor, MI
• Providers in Ann Arbor, MI by specialty
• Endocrinology, Diabetes & Metabolism Physician in Michigan

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Oct 2, 2025; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.