Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Jason A. Efstathiou, MD

Individual provider Radiation Oncology Physician · NPI 1598967523

Jason A. Efstathiou, MD is a Radiation Oncology in Boston, Massachusetts. Graduated from Harvard Medical School in 2003, 23 years ago. Practices with The General Hospital Corporation, a 1,276-clinician group, works from 2 locations, accepts Medicare assignment and offers telehealth. Licensed in Massachusetts.

Years since qualifying
23
Trained at
Harvard Medical School
Licensed in
MA
In the registry since
2007
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Partly verified

Some contact details are missing from the federal record.

Massachusetts General Hospital 55 Fruit St
Boston, MA 02114
Phone: (617) 726-1160
Show map & directions

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

Radiation Oncology Physician (primary) Taxonomy 2085R0001X · Licence 235571 (MA)

Record details

NPI number1598967523
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJune 1, 2007
Last updated in NPPESFebruary 6, 2026
Certification dateFebruary 6, 2026
Mailing addressMassachusetts General Hospital, 55 Fruit Street, Boston, MA 02114

Medicare enrollment

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

Medicare specialtyRADIATION ONCOLOGY
Medical schoolHARVARD MEDICAL SCHOOL
Graduated 2003 (23 years in practice)
Group practice The General Hospital Corporation — 1276 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations2 on file with Medicare

Other providers in Boston