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Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DR. ROBERT SACKSTEIN MD PHD
NPI 1306887302
Internal Medicine in Boston, MA

Active since June 09, 2006
100 BLOSSOM STREET, HEMATOLOGY ONCOLOGY ASSOCIATES COX6, BOSTON, MA 02114(617) 724-1124(617) 724-1126 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 09, 2026.

Record update history: Jul 13, 2026, Sep 11, 2025 (2 updates tracked since 2025).

About Dr. Robert Sackstein Md Phd NPPES

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

DR. ROBERT SACKSTEIN MD PHD (NPI 1306887302) is an individual internal medicine provider in Boston, Massachusetts, licensed in Massachusetts (155205) and active in the NPI registry since June 2006.

NPPES Registry Identity

NPI1306887302
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameDR. ROBERT SACKSTEINCredential: MD PHD
Location Address100 BLOSSOM STREET, HEMATOLOGY ONCOLOGY ASSOCIATES COX6Boston, MA 02114-2617
Mailing AddressPo Box 9142, Mass General Physician OrganizationCharlestown, MA 02129-9142 · (617) 724-0287 · Fax (617) 726-2894
Phone(617) 724-1124
Fax(617) 724-1126
Sole ProprietorNo
Enumeration DateJune 9, 2006
Last NPPES UpdateJuly 13, 20262 updates tracked since enumeration
✔ NPI 1306887302 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in MA · 155205
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
Also ListedInternal Medicine · HematologyTaxonomy 207RH0000X · License 155205 (MA)
100 BLOSSOM STREET, Boston, MA 02114
Open in Google Maps ↗

Other Identifiers 3

Other155205MA · Tufts Health Plan
Medicaid3186768MA
OtherJ19433MA · Bcbs Ma

Other Providers at the Same Location NPPES 11

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

DR. THOMAS G ROBERTS JR. MD
Internal Medicine (Hematology & Oncology)
100 BLOSSOM STREET, COX 640 HEMATOLOGY ONCOLOGY ASSOCIATES
BOSTON, MA 02114
Suffolk County (617) 726-7423
MR. MARC GILBERT BOLDUC LICSW, CADC II, CGP
Social Worker (Clinical)
100 BLOSSOM STREET, COX BUILDING, FIRST FLOOR
BOSTON, MA 02114
Suffolk County (617) 726-6185
DR. JOANNA M STRECK PHD
Psychologist
100 BLOSSOM STREET, COX 110
BOSTON, MA 02114
Suffolk County (617) 643-9977
DR. ALEENA BANERJI MD
Allergy & Immunology
100 BLOSSOM STREET, COX 201
BOSTON, MA 02114
Suffolk County (617) 726-3850
NANCY J SCHAEFFER NP
Nurse Practitioner
100 BLOSSOM STREET, COX 1 HEMATOLOGY ONCOLOGY ASSOCIATES
BOSTON, MA 02114
Suffolk County (617) 726-8698
DR. OTHON ILIOPOULOS MD
Internal Medicine (Medical Oncology)
100 BLOSSOM STREET, YAW 7 MASSACHUSETTS GENERAL HOSPITAL
BOSTON, MA 02114
Suffolk County (617) 724-3404
DR. BRUCE ALLAN CHABNER MD
Internal Medicine
100 BLOSSOM STREET, COX 640 HEMATOLOGY ONCOLOGY ASSOCIATES
BOSTON, MA 02114
Suffolk County (617) 724-3200
SHANNON M MACDONALD MD
Radiology (Radiation Oncology)
100 BLOSSOM STREET, COX 3
BOSTON, MA 02114
Suffolk County (617) 724-8196

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 Robert Sackstein's NPI number?

The NPI number for Robert Sackstein is 1306887302. It was assigned to this individual provider in the NPPES registry on June 9, 2006.

Where is Robert Sackstein located?

Robert Sackstein practices at 100 Blossom Street Hematology Oncology Associates Cox6, Boston, MA 02114. The listed phone number is (617) 724-1124.

What is Robert Sackstein's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

When was this NPI record last updated?

The NPPES record for Robert Sackstein was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 33 days 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.