NPPES file of Aug 9, 2026

Claus Hamann, MD

Geriatric Medicine (Internal Medicine) Physician · Westborough, MA

Claus Hamann, MD is a geriatric medicine (internal medicine) physician with a practice address in Westborough, Massachusetts, and NPI 1861483752, issued on Oct 31, 2005. Check the license (Massachusetts 75389, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1861483752
Name
Claus Hamann
Credential
MD
Primary taxonomy
Geriatric Medicine (Internal Medicine) Physician 207RG0300X
License numbers
75389 MA
MD20639 ME
Self-reported in NPPES; status is on the state search
Practice location
1400 Computer Dr Ste 301, Westborough, MA 01581
Phone
(617) 420-5316
Enumerated
Oct 31, 2005
Record last updated
Jan 3, 2020 (not updated in 6 years: call before relying on the address or phone)
Medicaid ID
3106594 MA
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
Download card Updates feed

8 nearest geriatric medicine (internal medicine) physician records → All 225 in Massachusetts → Look up another NPI →

Also registered at 1400 Computer Dr Ste 301

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Wanda Colon-Cartagena, M.D.Geriatric Medicine (Internal Medicine) Physician1629300256
  2. Michelle Debest, N.P.Adult Health Nurse Practitioner1538252093
  3. Minh Huong Fay, FNPFamily Nurse Practitioner1144377755
  4. Jeremy Freund, NPPsychiatric/Mental Health Nurse Practitioner1588621122
  5. Heather Gustafson, PA-CPhysician Assistant1538541883
  6. Jennifer Hilgenberg, PA-CPhysician Assistant1093846578

Verify Claus Hamann in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
    Search for license 75389    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the Massachusetts license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

Is this page about you? You can ask us to correct, restrict or remove it: how.

Claus Hamann among 225 geriatric medicine (internal medicine) physician records in Massachusetts

Claus Hamann, MD is one of 225 geriatric medicine (internal medicine) physician records with a practice address in Massachusetts. 71% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2005, is newer than 0% of them.

  • NPI issued2005 · 0% of these records are older, 86% newer
  • In a Medicare fileNo · 71% of these records are
  • In the CMS Doctors and Clinicians fileNo · 53% of these records are
  • Record last updated2020 · 63% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0300X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Geriatric Medicine (Internal Medicine) Physician providers in Massachusetts

There are 225 geriatric medicine (internal medicine) physician records in Massachusetts. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

All 225 in Massachusetts → Every provider in Westborough → Geriatric Medicine (Internal Medicine) Physician nationwide →

The 8 geriatric medicine (internal medicine) physician records with the nearest ZIP codes

  1. Wanda Colon-Cartagena, M.D.Westborough, MA 015811629300256
  2. Anthony Zizza, M.D.Westborough, MA 015811134430747
  3. Hawa Abu, MDWorcester, MA 016051104441229
  4. Linsey BarkerWorcester, MA 016051356847974
  5. Jeffrey Burl, MDWorcester, MA 016051699749309
  6. David Dosa, MDWorcester, MA 016051417901687
  7. Kouta Ito, M.D., M.S.Worcester, MA 016051295905115
  8. Suhasini Iyer, M.D.Worcester, MA 016051063495943

Common questions

What is Claus Hamann, MD's NPI number?

Claus Hamann, MD's National Provider Identifier (NPI) is 1861483752, issued on Oct 31, 2005. An NPI identifies a provider in billing; it is not a license.

Where is Claus Hamann, MD located?

The NPPES record lists a practice address at 1400 Computer Dr Ste 301, Westborough, MA, 01581. Phone: (617) 420-5316. Providers update this record themselves, so call before visiting.

How can I verify Claus Hamann, MD's license?

NPPES lists Massachusetts license number 75389, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.