NPPES file of Aug 9, 2026

Gordon Harold Williams, MD

Endocrinology, Diabetes & Metabolism Physician · Boston, MA

Gordon Harold Williams, MD is an endocrinology, diabetes & metabolism physician with a practice address in Boston, Massachusetts, and NPI 1477503993, issued on May 12, 2006. Check the license (Massachusetts 29417, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1477503993
Name
Gordon Harold Williams
Credential
MD
Primary taxonomy
Endocrinology, Diabetes & Metabolism Physician 207RE0101X
License number
29417 MA
Self-reported in NPPES; status is on the state search
Practice location
221 Longwood Avenue Rfb2, Boston, MA 02115
Phone
(617) 732-5661
Enumerated
May 12, 2006
Record last updated
Jul 13, 2026
Medicare enrollment
Enrolled (PECOS I20100310000729); accepts Medicare assignment
Medical or professional school
Harvard Medical School, 1963
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 221 Longwood Avenue Rfb2

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

  1. Erik Alexander, MDEndocrinology, Diabetes & Metabolism Physician1285692376
  2. Ellen Seely, MDEndocrinology, Diabetes & Metabolism Physician1407814023

Verify Gordon Harold Williams 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 29417
    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

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96% fewer Medicare Part D claims than the average endocrinology, diabetes & metabolism physician in 2024

118 Medicare Part D claims for 18 beneficiaries, against an average of 2,630 among the 8,223 providers of this specialty who prescribed in Part D.

  1. Gordon Williams118
  2. Specialty average2,630

Most prescribed

  1. Levothyroxine Sodium31 claims
  2. Synthroid18 claims
  3. Hydrocortisone16 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.

Bills Medicare through one group practice

  1. Brigham And Womens Physicians Organization IncBoston, MA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Gordon Harold Williams among 522 endocrinology, diabetes & metabolism physician records in Massachusetts

Gordon Harold Williams, MD is one of 522 endocrinology, diabetes & metabolism physician records with a practice address in Massachusetts. 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 14% of them.

  • NPI issued2006 · 14% of these records are older, 52% newer
  • In a Medicare fileYes · 82% of these records are
  • In the CMS Doctors and Clinicians fileYes · 72% of these records are
  • Graduated1963 · median 2002 among the 378 with a school on file
  • Record last updated2026 · 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 Massachusetts 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 Massachusetts

There are 522 endocrinology, diabetes & metabolism physician records in Massachusetts.

The 8 endocrinology, diabetes & metabolism physician records with the nearest ZIP codes

  1. Gail Adler, MD PHDBoston, MA 021151780675280
  2. Shehzad Basaria, MDBoston, MA 021151699730101
  3. Edward Brown, MDBoston, MA 021151871550137
  4. Margo Hudson, MDBoston, MA 021151922065242
  5. Ursula Kaiser, MDBoston, MA 021151053377374
  6. Nikheel Kolatkar, M.D.Boston, MA 021151396748463
  7. P Larsen, MDBoston, MA 021151700842952
  8. Meryl Leboff, MDBoston, MA 021151235106030

Common questions

What is Gordon Harold Williams, MD's NPI number?

Gordon Harold Williams, MD's National Provider Identifier (NPI) is 1477503993, issued on May 12, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Gordon Harold Williams, MD located?

The NPPES record lists a practice address at 221 Longwood Avenue Rfb2, Boston, MA, 02115. Phone: (617) 732-5661. Providers update this record themselves, so call before visiting.

How can I verify Gordon Harold Williams, MD's license?

NPPES lists Massachusetts license number 29417, 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.

How much does Gordon Harold Williams, MD prescribe under Medicare Part D?

In 2024, Gordon Harold Williams, MD had 118 Medicare Part D claims for 18 beneficiaries; 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.