Gary Douglas Hammer, MD
Endocrinology, Diabetes & Metabolism Physician · Ann Arbor, MI
Gary Douglas Hammer, MD is an endocrinology, diabetes & metabolism physician with a practice address in Ann Arbor, Michigan, and NPI 1871676791, issued on Oct 23, 2006. Check the license (Michigan 4301075475, as entered in NPPES) on the Michigan Board of Medicine (LARA); the Medicare figures below come from public CMS files.
- Name
- Gary Douglas Hammer
- Credential
- MD
- Primary taxonomy
- Endocrinology, Diabetes & Metabolism Physician 207RE0101X
- License number
- 4301075475 MI
Self-reported in NPPES; status is on the state search - Practice location
- 1500 E Medical Center Dr, Ann Arbor, MI 48109
- Phone
- (734) 936-4000
- Enumerated
- Oct 23, 2006
- Record last updated
- Oct 2, 2025
- Medicaid ID
- 4177663 MI
- Medicare enrollment
- Enrolled (PECOS I20100122000243); accepts Medicare assignment
- Medical or professional school
- Tufts University School Of Medicine, 1992
- Entity
- Type 1 · individual
8 nearest endocrinology, diabetes & metabolism physician records → All 270 in Michigan → Look up another NPI →
Also registered at 1500 E Medical Center Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Bryan Aaron, MDObstetrics & Gynecology Physician1578307724
- Keith Aaronson, MDAdvanced Heart Failure and Transplant Cardiology Physician1144305301
- Rajani Aatre, M.S., M.SC.Genetic Counselor (M.S.)1962122457
- Anjelica Abate, MDDiagnostic Radiology Physician1841819216
- Nicole Abbott, CRNACertified Registered Nurse Anesthetist1790329860
- Ahmed Abdel-Latif, M.D.Interventional Cardiology Physician1518181239
Verify Gary Douglas Hammer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMichigan Board of Medicine (LARA)
Search for license 4301075475Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024
45 Medicare Part D claims, against an average of 2,630 among the 8,223 providers of this specialty who prescribed in Part D. Brand-name drugs were 36% of claims.
Most prescribed
- Hydrocortisone25 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $5,000.00
1 payment: consulting fee; the largest payer was Neurocrine Biosciences, Inc. The 5,661 providers of this specialty with any payment received $5,742.15 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Regents OF The University OF MichiganAnn Arbor, MI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gary Douglas Hammer among 270 endocrinology, diabetes & metabolism physician records in Michigan
Gary Douglas Hammer, MD is one of 270 endocrinology, diabetes & metabolism physician records with a practice address in Michigan. 82% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 7% of them.
- NPI issued2006 · 7% of these records are older, 58% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated1992 · median 2004 among the 195 with a school on file
- Record last updated2025 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RE0101X and a Michigan practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Endocrinology, Diabetes & Metabolism Physician providers in Michigan
There are 270 endocrinology, diabetes & metabolism physician records in Michigan.
All 270 in Michigan → Every provider in Ann Arbor → Endocrinology, Diabetes & Metabolism Physician nationwide →
The 8 endocrinology, diabetes & metabolism physician records with the nearest ZIP codes
- Ariel Barkan, MDAnn Arbor, MI 481091891877320
- William Herman, MDAnn Arbor, MI 481091316020233
- Shafaq Khairi, M.D.Ann Arbor, MI 481091225284334
- Ronald Koenig, MDAnn Arbor, MI 481091982787818
- Julia MeirelesAnn Arbor, MI 481091760052773
- Richard Mortensen, MDAnn Arbor, MI 481091194962530
- Joanna Spencer-Segal, MDAnn Arbor, MI 481091609161611
- Mary TownsendAnn Arbor, MI 481091891431946
Common questions
What is Gary Douglas Hammer, MD's NPI number?
Gary Douglas Hammer, MD's National Provider Identifier (NPI) is 1871676791, issued on Oct 23, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Gary Douglas Hammer, MD located?
The NPPES record lists a practice address at 1500 E Medical Center Dr, Ann Arbor, MI, 48109. Phone: (734) 936-4000. Providers update this record themselves, so call before visiting.
How can I verify Gary Douglas Hammer, MD's license?
NPPES lists Michigan license number 4301075475, as entered by the provider. Search the Michigan Board of Medicine (LARA) at https://aca-prod.accela.com/MILARA/GeneralProperty/PropertyLookUp.aspx?isLicensee=Y&TabName=APO. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gary Douglas Hammer, MD prescribe under Medicare Part D?
In 2024, Gary Douglas Hammer, MD had 45 Medicare Part D claims; the average among endocrinology, diabetes & metabolism physician prescribers was 2,630. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.