Gerald I Kassels, M.D.

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

36953 Issued in MA

Practice address

125 Nashua St
Boston, MA 02114-1101

Phone

(616) 573-7110

NPI assigned

Nov 18, 2005

Sex

Male

Sole proprietor

No

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

Specialties & licenses 1

Addresses

Other identifiers 1

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

HospitalistAlso: Internal Medicine

Education

Rush Medical College of Rush University, 1973

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

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

Practice addresses (Care Compare)

Hospital & facility affiliations

• Massachusetts General Hospital Hospital, Boston, MA, CCN 220071

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: kassels.gerald.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 and National Provider Directory roles.

• 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 NPD
• General Hospital Corp

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1508390014
  NPD

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

• 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": "1132272000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1783900800000",
    "number": "1093797599",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "19 RANSOM RD",
            "city": "NEWTON CENTRE",
            "state": "MA",
            "postal_code": "024591106",
            "telephone_number": "617-332-1644"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "125 NASHUA ST",
            "city": "BOSTON",
            "state": "MA",
            "postal_code": "021141101",
            "telephone_number": "616-573-7110"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "KASSELS",
        "first_name": "GERALD",
        "middle_name": "I",
        "name_prefix": "Dr.",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2005-11-18",
        "last_updated": "2026-07-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "MA",
            "license": "36953",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "2049732",
            "state": "MA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Elizabeth Kass, M.D.
• Dawit Worku Kassa
• Bina Kassamali, MD
• Ahmad Kassar, MD
• Monica H Kassavin, MD
• James R Kasser, MD
• Zachary Kassir
• Jonathan Kassira, MD
• Marilyn Rita Kassirer, MD
• Samer Kastali, D.D.S, M.S.

• Internal Medicine Physician in Boston, MA
• Providers in Boston, MA by specialty
• Internal Medicine Physician in Massachusetts

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jul 13, 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.