Steven Jay Isakoff, MD PHD

Primary specialty

Hematology & Oncology PhysicianTaxonomy code 207RH0003X

License

218952 Issued in MA

Practice address

55 Fruit St
Boston, MA 02114-2621

Phone

(617) 726-6500

Fax

(617) 724-1079

NPI assigned

May 23, 2006

Last updated

Aug 11, 2026By the provider in NPPES

Sex

Male

Sole proprietor

No

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 3

Addresses

Medicare fee-for-service enrollment

Enrolled in MA

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 1

Specialty

Medical OncologyAlso: Internal Medicine

Education

New York University School of Medicine, 2000

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Telehealth

Offers telehealth services

Group practices

The General Hospital CorporationGroup PAC ID 6507803806, 1,275 clinicians

Massachusetts General Physicians Organization IncGroup PAC ID 2466365820, 3,494 clinicians

Brigham and Womens Physicians Organization IncGroup PAC ID 3870405988, 2,931 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Massachusetts General Hospital Hospital, Boston, MA, CCN 220071
• North Shore Medical Center - Hospital, Salem, MA, CCN 220035
• Brigham and Women's Hospital Hospital, Boston, MA, CCN 220110
• Newton-Wellesley Hospital Hospital, Newton, MA, CCN 220101
• Martha's Vineyard Hospital Inc Hospital, Oak Bluffs, MA, CCN 221300

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine, Doctor of Philosophy

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: isakoff.steven.mgh@direct.partners.masshiway.net

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships, National Provider Directory roles and organizations whose NPPES authorized official is this provider.

• Brigham & Womens Physicians Organization Inc

  • Internal Medicine Physician
  • Boston, MA
  • NPI 1033535497
  Medicare reassignment Care Compare group NPD
• Massachusetts General Physicians Organization Inc

  • Dermatology Physician
  • Boston, MA
  • NPI 1801874573

  Internal Medicine

  Medicare reassignment Care Compare group NPD
• The General Hospital Corporation

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1023049236
  Medicare reassignment Care Compare group NPD
• General Hospital Corp

  dba Massachusetts General Hospital Outpatient Pharmacy

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1508390014
  NPD
• Brigham and Womens Physicians Organization Inc

  • Diagnostic Radiology Physician
  • Boston, MA
  • NPI 1265464598
  NPD (past)
• Massachusetts General Hospital

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1578842498
  NPD (past)

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

• Brigham & Womens Hospital, Inc.

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1790717650
  Care Compare affiliation
• Martha's Vineyard Hospital, Inc.

  • Critical Access Hospital
  • Oak Bluffs, MA
  • NPI 1134206386
  Care Compare affiliation
• Newton-Wellesley Hospital

  • General Acute Care Hospital
  • Newton, MA
  • NPI 1992737761
  Care Compare affiliation
• North Shore Medical Center, Inc.

  dba Salem Hospital

  • General Acute Care Hospital
  • Salem, MA
  • NPI 1730121633
  Care Compare affiliation
• The General Hospital Corporation

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1023049236
  Care Compare affiliation

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1148342400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1786406400000",
    "number": "1447205042",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "PO BOX 9142",
            "address_2": "MASS GENERAL PHYSICIANS ORGANIZATION INC",
            "city": "CHARLESTOWN",
            "state": "MA",
            "postal_code": "021299142",
            "telephone_number": "617-726-6500",
            "fax_number": "617-724-1079"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "55 FRUIT ST",
            "city": "BOSTON",
            "state": "MA",
            "postal_code": "021142621",
            "telephone_number": "617-726-6500",
            "fax_number": "617-724-1079"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "75 Francis St",
            "address_purpose": "LOCATION",
            "city": "Boston",
            "state": "MA",
            "postal_code": "021156110",
            "country_code": "US",
            "telephone_number": "617-732-5500",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "1153 Centre St",
            "address_purpose": "LOCATION",
            "city": "Jamaica Plain",
            "state": "MA",
            "postal_code": "021303446",
            "country_code": "US",
            "telephone_number": "617-724-4000",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "ISAKOFF",
        "first_name": "STEVEN",
        "middle_name": "JAY",
        "name_prefix": "Dr.",
        "credential": "MD PHD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-05-23",
        "last_updated": "2026-08-11",
        "certification_date": "2026-08-11",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RH0003X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Hematology & Oncology",
            "state": "MA",
            "license": "218952",
            "primary": true
        },
        {
            "code": "207RX0202X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Medical Oncology",
            "state": "MA",
            "license": "218952",
            "primary": false
        },
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "MA",
            "license": "218952",
            "primary": false
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Colleen G Isabelle
• Andrew Isac
• Maksim Isachanka, M.D.
• Tristan Isacksen, NP
• Federica Isaia
• Imari-Ashley Palma Isaksen, PHD
• Ameesh M Isath, M.B.B.S
• Nicolas Isaza Valencia, MD
• Erin Isaza
• Elvira Isganaitis, MD, MPH

• Hematology & Oncology Physician in Boston, MA
• Providers in Boston, MA by specialty
• Hematology & Oncology Physician in Massachusetts

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Aug 11, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.