1. Home
  2. Directory
  3. Massachusetts
  4. Boston
  5. Internal Medicine
  6. NPI Profile

LEON PAPPAS MD, PHD
NPI 1164910519
Internal Medicine - Medical Oncology in Boston, MA

Active since May 01, 2018PECOS EnrolledAccepts Medicare Assignment

NPPES record last updated: February 10, 2026. Verified against the NPPES registry weekly; last sync: August 16, 2026.

About Leon Pappas Md, Phd NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

LEON PAPPAS MD, PHD (NPI 1164910519) is an individual medical oncology provider in Boston, Massachusetts, licensed in Massachusetts (1016384) and active in the NPI registry since May 2018. He is enrolled in Medicare PECOS, is affiliated with Massachusetts General Hospital, and is a graduate of Boston University School Of Medicine (2018).

NPPES Registry Identity

NPI1164910519
Entity TypeIndividualMale
Primary Taxonomy207RX0202X
Provider Legal NameLEON PAPPASCredential: MD, PHD
Location Address55 FRUIT STBoston, MA 02114-2621
Mailing Address55 Fruit StBoston, MA 02114-2621 · (617) 726-2000
Phone(617) 643-0596
Sole ProprietorNo
Medical School CMSBoston University School Of MedicineGraduated 2018
Enumeration DateMay 1, 2018
Last NPPES UpdateFebruary 10, 2026
NPPES CertifiedFebruary 10, 2026
✔ NPI 1164910519 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · Medical OncologyAllopathic & Osteopathic Physicians
Taxonomy Code207RX0202X
License✔ Licensed in MA · 1016384
Definition
An internist who specializes in the diagnosis and treatment of all types of cancer and other benign and malignant tumors. This specialist decides on and administers therapy for these malignancies as well as consults with surgeons and radiotherapists on other treatments for cancer.
Also ListedInternal MedicineTaxonomy 207R00000X · License 1016384 (MA)
55 FRUIT ST, Boston, MA 02114
Open in Google Maps ↗

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Leon Pappas Md, Phd is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID5698004919
PECOS Enrollment IDI20240606003123
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 4

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Prolonged office or other outpatient evaluation and management service(s) beyond the maximum required time of the primary procedure which has been selected using total time on the date of the primary service; each additional 15 minutes by the physician or G2212
This service refers to extended doctor visits where your healthcare provider spends additional time evaluating and managing your health beyond the primary procedure's required time. This includes each extra 15 minutes spent by the physician on the same day as the primary service.
71 services25 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
56 services31 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
25 services16 patients
Prolonged office or other outpatient evaluation and management service(s) beyond the maximum required time of the primary procedure which has been selected using total time on the date of the primary service; each additional 15 minutes by the physician or G2212
This service refers to extended doctor visits where your healthcare provider spends additional time evaluating and managing your health beyond the primary procedure's required time. This includes each extra 15 minutes spent by the physician on the same day as the primary service.
22 services13 patients

Hospital Affiliations CMS Care Compare 3

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Massachusetts General Hospital

Acute Care Hospitals · Boston, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220071
Location55 Fruit StreetBoston, MA 02114 · Suffolk County
Emergency services Birthing friendly

Massachusetts Eye And Ear Infirmary -

Acute Care Hospitals · Boston, MA
OwnershipVoluntary non-profit - Private
CMS Certification Number220075
Location243 Charles StreetBoston, MA 02114 · Suffolk County
Emergency services

Brigham And Women's Hospital

Acute Care Hospitals · Boston, MA
5/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number220110
Location75 Francis StreetBoston, MA 02115 · Suffolk County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 02114 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$189.86 typical visit price
range $63.72 – $189.86
Typical copayment $47.46 (range $15.93 – $47.46)
Most-billed visit code 99205
Established Patient
$111.18 typical visit price
range $21.07 – $155.29
Typical copayment $27.79 (range $5.26 – $38.82)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

STUTI GIRISH SHROFF MD, MBBS
Pathology (Anatomic Pathology)
55 FRUIT ST
BOSTON, MA 02114
Suffolk County (617) 726-2971
NANCY WANG M.D.
Internal Medicine (Hematology & Oncology)
55 FRUIT ST
BOSTON, MA 02114
Suffolk County (017) 724-4000
DR. DUSAN HANIDZIAR M.D., PH.D.
Anesthesiology
55 FRUIT ST, GRAY-BIGELOW 444
BOSTON, MA 02114
Suffolk County (617) 726-3030
JOHN JOSEPH DANKO DO
Physical Medicine & Rehabilitation
55 FRUIT ST
BOSTON, MA 02114
Suffolk County (617) 726-2000
DR. MICHAEL ANDREW LOBRITZ M.D, PH.D.
Internal Medicine (Infectious Disease)
55 FRUIT ST, DIVISION OF INFECTIOUS DISEASE, GRJ-504
BOSTON, MA 02114
Suffolk County (617) 724-9248
MS. KELLY ELISHA TRECARTIN NP
Nurse Practitioner (Acute Care)
55 FRUIT ST, BIGALOW 852 F
BOSTON, MA 02114
Suffolk County (617) 726-7400
JAMIE MARIE ALLEN NP
Nurse Practitioner
55 FRUIT ST
BOSTON, MA 02114
Suffolk County (617) 724-4410
DR. DHAVAL SANJEEV KOLTE M.B.B.S., PH.D.
Internal Medicine (Cardiovascular Disease)
55 FRUIT ST
BOSTON, MA 02114
Suffolk County (617) 643-3238

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Leon Pappas's NPI number?

The NPI number for Leon Pappas is 1164910519. It was assigned to this individual provider in the NPPES registry on May 1, 2018.

Where is Leon Pappas located?

Leon Pappas practices at 55 Fruit St, Boston, MA 02114. The listed phone number is (617) 643-0596.

What is Leon Pappas's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Medical Oncology, with taxonomy code 207RX0202X.

Is Leon Pappas enrolled in Medicare?

Yes. Leon Pappas is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Is Leon Pappas affiliated with any hospitals?

According to CMS data, Leon Pappas is affiliated with Massachusetts General Hospital, Massachusetts Eye And Ear Infirmary - and Brigham And Women's Hospital.

When was this NPI record last updated?

The NPPES record for Leon Pappas was last updated on February 10, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.