Individual provider Active NPI

Rebecca Sara Karp, M.D.

  • Hematology & Oncology Physician
  • Boston, MA
National Provider Identifier
1265669659
Registry record updated Aug 13, 2026
On this page

Key facts

NPPES NPI Registry
Primary specialty
Hematology & Oncology PhysicianTaxonomy code 207RH0003X
License
251249 Issued in MA
Practice address
55 Fruit St
Boston, MA 02114-2696
Phone
(866) 493-1612
NPI assigned
Jun 12, 2009
Sex
Female
Sole proprietor
No

NPPES NPI Registry

Updated by the provider on Aug 13, 2026

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

Specialties & licenses 2

Specialty (taxonomy)CodeLicenseStatePrimary
Hematology & Oncology Physician 207RH0003X 251249 MA Primary
Medical Oncology Physician 207RX0202X 251249 MA

Addresses

Primary practice location

55 Fruit St
Boston, MA 02114-2696

Mailing address

330 Brookline Ave
Boston, MA 02215-5400
Phone (617) 667-2100

Other practice location 1

330 Brookline Ave
Boston, MA 02215-5400
Phone (617) 667-2100

Other practice location 2

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

Medicare participation

Medicare enrollment files
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

Enrollment IDStateProvider typePAC IDDetails
I20120822000250 MA Practitioner - Hematology/OncologyPractitioner - Internal Medicine 5698922953 Reassigns benefits to 3 organizations

Care Compare profile

Medicare Care Compare
Specialty
Hematology/OncologyAlso: Internal Medicine
Education
Icahn School of Medicine at Mount Sinai, 2009
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

Practice addresses (Care Compare)

40 2ND Ave
Waltham, MA 02451-1132
Phone (781) 487-2900

55 Fruit St
Boston, MA 02114-2621
Phone (617) 726-2000

55 Fruit St
Boston, MA 02114-2696
Phone (617) 724-0287

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
  • Cooley Dickinson Hospital Inc,the Hospital, Northampton, MA, CCN 220015

National Provider Directory

National Provider Directory
Medicare enrollment (NPD)
Enrolled
Credentials
Doctor of Medicine

Practice roles

OrganizationSpecialtyStatusNew patients
Massachusetts General Physicians Organization Inc CurrentSince Jul 5, 2016 Accepting new patients
The General Hospital Corporation CurrentSince Jul 5, 2016 Accepting new patients
Brigham & Womens Physicians Organization Inc CurrentSince Jan 12, 2026 Accepting new patients
General Hospital Corp Current Accepting new patients
Brigham and Womens Physicians Organization Inc Past Accepting new patients

Locations

55 Fruit St
#2
Boston, MA 02114
Phone (617) 726-2967

75 Francis St
Boston, MA 02115

55 Fruit St
Boston, MA 02114

Interoperability endpoints

  • Direct secure messaging: karp.rebecca.mgh@direct.partners.masshiway.net

Organizations & group practices 5

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

Hospital & facility affiliations 6

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

NPI Registry JSON

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

{
    "created_epoch": "1244764800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1786579200000",
    "number": "1265669659",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "330 BROOKLINE AVE",
            "city": "BOSTON",
            "state": "MA",
            "postal_code": "022155400",
            "telephone_number": "617-667-2100",
            "fax_number": "617-975-5665"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "55 FRUIT ST",
            "city": "BOSTON",
            "state": "MA",
            "postal_code": "021142696",
            "telephone_number": "866-493-1612"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "330 Brookline Ave",
            "address_purpose": "LOCATION",
            "city": "Boston",
            "state": "MA",
            "postal_code": "022155400",
            "country_code": "US",
            "telephone_number": "617-667-2100",
            "fax_number": "617-975-5665",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "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"
        }
    ],
    "basic": {
        "last_name": "KARP",
        "first_name": "REBECCA",
        "middle_name": "SARA",
        "name_prefix": "Dr.",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "F",
        "enumeration_date": "2009-06-12",
        "last_updated": "2026-08-13",
        "certification_date": "2026-08-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RH0003X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Hematology & Oncology",
            "state": "MA",
            "license": "251249",
            "primary": true
        },
        {
            "code": "207RX0202X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Medical Oncology",
            "state": "MA",
            "license": "251249",
            "primary": false
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

Other providers in Boston, MA

Sources for this page

Verify at the official NPI Registry.