NPPES file of Aug 9, 2026

Gregory T. Brennan, PA-C

Physician Assistant · Boston, MA

Gregory T. Brennan, PA-C is a physician assistant with a practice address in Boston, Massachusetts, and NPI 1629300124, issued on Feb 8, 2010. Check the license (Massachusetts PA4313, as entered in NPPES) with the Massachusetts board that licenses this profession; the Medicare figures below come from public CMS files.

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

NPPES recordNPPES file of Aug 9, 2026
1629300124
Name
Gregory T. Brennan
Credential
PA-C
Primary taxonomy
Physician Assistant 363A00000X
License numbers
PA4313 MA
0758 NH
Self-reported in NPPES; status is on the state search
Practice location
147 Milk St, Boston, MA 02109
Phone
(617) 559-8239
Enumerated
Feb 8, 2010
Record last updated
Jan 11, 2012 (not updated in 14 years: call before relying on the address or phone)
Fax
(617) 421-3487
Medicare enrollment
Enrolled (PECOS I20120515000035); accepts Medicare assignment
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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8 nearest physician assistant records → All 4,713 in Massachusetts → Look up another NPI →

Also registered at 147 Milk St

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

  1. Christopher Adams, M.D.Dermatology Physician1871777615
  2. Martha Bagby, LICSWClinical Social Worker1942251186
  3. Olivia Bane, FNPNurse Practitioner1053144956
  4. Linda Barnard, MS, APRN-BCNurse Practitioner1710994553
  5. John Beneski, D.C.Chiropractor1003973058
  6. Karen Bikofsky, NPAdult Health Nurse Practitioner1720337207

Verify Gregory T. Brennan in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWhich Massachusetts board licenses this profession
    Search for license PA4313    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
Find 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.

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Bills Medicare through one group practice

  1. Atrius Health IncNeedham, MA

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

Gregory T. Brennan among 4,713 physician assistant records in Massachusetts

Gregory T. Brennan, PA-C is one of 4,713 physician assistant records with a practice address in Massachusetts. 78% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2010, is newer than 22% of them.

  • NPI issued2010 · 22% of these records are older, 76% newer
  • In a Medicare fileYes · 78% of these records are
  • In the CMS Doctors and Clinicians fileYes · 68% of these records are
  • Graduated2009 · median 2019 among the 3,217 with a school on file
  • Record last updated2012 · 38% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363A00000X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

1,660 physician assistant records list a practice address in Boston

They are 1,660 of the 41,865 NPPES records with a practice address in Boston, and 4,713 physician assistant records in Massachusetts.

All 4,713 in Massachusetts → Every provider in Boston → Physician Assistant nationwide →

The 8 physician assistant records with the nearest ZIP codes

  1. Catherine Dam, PA, MPHBoston, MA 021091982239430
  2. Diane Foley, PABoston, MA 021091285698050
  3. Erin McNiffBoston, MA 021091376991497
  4. Nicolette MeloBoston, MA 021091770251845
  5. Suela Omeri, PA-CBoston, MA 021091073213088
  6. Scott Orrahood, PABoston, MA 021091376606061
  7. Lee Orsky, PABoston, MA 021091063513950
  8. Amanda Perillo, PA-CBoston, MA 021091033554241

Common questions

What is Gregory T. Brennan, PA-C's NPI number?

Gregory T. Brennan, PA-C's National Provider Identifier (NPI) is 1629300124, issued on Feb 8, 2010. An NPI identifies a provider in billing; it is not a license.

Where is Gregory T. Brennan, PA-C located?

The NPPES record lists a practice address at 147 Milk St, Boston, MA, 02109. Phone: (617) 559-8239. Providers update this record themselves, so call before visiting.

How can I verify Gregory T. Brennan, PA-C's license?

NPPES lists Massachusetts license number PA4313, as entered by the provider. Search the Massachusetts board that licenses this profession; the NPPES record confirms identity 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.

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.