Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Michael G Gregory, MD

Individual provider Internal Medicine Physician · NPI 1265457675

Michael G Gregory, MD practises Internal Medicine in Brookline, Massachusetts. Qualified in 1987, 39 years ago. Practices with Massachusetts General Physicians Organization Inc, a 3,484-clinician group and accepts Medicare assignment. Licensed in Massachusetts.

Years since qualifying
39
Licensed in
MA
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

135 Pleasant St Apt 206
Brookline, MA 02446-7142 Not confirmed with CMS for 19 years — call before visiting
Phone: (617) 731-8131
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence MA208255 (MA)

Record details

NPI number1265457675
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 13, 2006
Last updated in NPPESJuly 8, 2007

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Also practisesGERIATRIC MEDICINE, HOSPICE/PALLIATIVE CARE
Medical schoolOTHER
Graduated 1987 (39 years in practice)
Group practice Massachusetts General Physicians Organization Inc — 3484 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients107
Services billed 979 a service is one billed item, such as a visit, a test or a procedure
Average patient age72

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $55 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Massachusetts General Physicians Organization Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 3484 clinicians in the practice; 12 are shown here.

Other providers in Brookline