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

Leon Pappas, MD, PHD

Individual provider Medical Oncology Physician · NPI 1164910519

Leon Pappas, MD, PHD practises Internal Medicine in Boston, Massachusetts. Graduated from Boston University School of Medicine in 2018, 8 years ago. Practices with Brigham and Womens Physicians Organization Inc, a 2,916-clinician group, works from 2 locations, accepts Medicare assignment and offers telehealth. Licensed in Massachusetts.

Years since qualifying
8
Trained at
Boston University School of Medicine
Licensed in
MA
In the registry since
2018
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.
PHD — Doctor of Philosophy
A research doctorate. In healthcare it usually sits alongside a clinical licence.

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Practice location Address checks out

55 Fruit St
Boston, MA 02114-2621
Phone: (617) 643-0596
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 75 Francis St, Boston, MA 02115-6110 — (617) 732-5500

Specialties & licences

Medical Oncology Physician (primary) Taxonomy 207RX0202X · Licence 1016384 (MA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 1016384 (MA)

Record details

NPI number1164910519
Entity typeIndividual (Type 1)
GenderMale
Credentials MD , PHD
Sole proprietorNo
NPI enumeratedMay 1, 2018
Last updated in NPPESFebruary 10, 2026
Certification dateFebruary 10, 2026

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolBOSTON UNIVERSITY SCHOOL OF MEDICINE
Graduated 2018 (8 years in practice)
Group practice Brigham And Womens Physicians Organization Inc — 2916 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations3 on file with Medicare

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 patients50
Services billed 304 a service is one billed item, such as a visit, a test or a procedure
Average patient age71

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.

Consulting Fee $4,720 2 payments
Food and Beverage $451 5 payments · a meal or drink at a meeting or visit, not a fee
Travel and Lodging $300 2 payments · travel or lodging paid or reimbursed, such as to attend a conference

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 Brigham and Womens Physicians Organization Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 2916 clinicians in the practice; 12 are shown here.

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