Issam A Oneyssi, M.D.

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

76569 Issued in MA

Practice address

100 South St
Southbridge, MA 01550-4051

Phone

(508) 765-9771

Fax

(508) 909-7735

NPI assigned

May 1, 2006

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

Internal Medicine

Education

Other, 1990

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Umass Memorial Medical Group IncGroup PAC ID 4284539891, 2,494 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Brookhaven Hospice Hospice, Marlborough, MA, CCN 221586
• Umass Memorial Health - Harrington Hospital Hospital, Southbridge, MA, CCN 220019

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

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.

• Umass Memorial Medical Group Inc

  • Internal Medicine Physician
  • Worcester, MA
  • NPI 1760445373
  Medicare reassignment Care Compare group
• Emerson Practice Associates, Inc.

  • Internal Medicine Physician
  • Concord, MA
  • NPI 1508020199
  Medicare reassignment
• Umass Memorial Health-Harrington Hospital Inc

  • General Acute Care Hospital
  • Southbridge, MA
  • NPI 1790780047
  NPD (past)

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

• Brookhaven Hospice LLC

  • Community Based Hospice Care Agency
  • Marlborough, MA
  • NPI 1730361742
  Care Compare affiliation
• Umass Memorial Health-Harrington Hospital Inc

  • General Acute Care Hospital
  • Southbridge, MA
  • NPI 1790780047
  Care Compare affiliation

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

{
    "created_epoch": "1146441600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1759363200000",
    "number": "1528026622",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "100 SOUTH ST",
            "city": "SOUTHBRIDGE",
            "state": "MA",
            "postal_code": "015504051",
            "telephone_number": "508-765-9771",
            "fax_number": "508-909-7735"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "100 SOUTH ST",
            "city": "SOUTHBRIDGE",
            "state": "MA",
            "postal_code": "015504051",
            "telephone_number": "508-765-9771",
            "fax_number": "508-909-7735"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "421 N Main St",
            "address_purpose": "LOCATION",
            "city": "Leeds",
            "state": "MA",
            "postal_code": "010539764",
            "country_code": "US",
            "telephone_number": "413-584-4040 x2461",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "ONEYSSI",
        "first_name": "ISSAM",
        "middle_name": "A",
        "name_prefix": "Dr.",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-05-01",
        "last_updated": "2025-10-02",
        "certification_date": "2025-10-02",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "MA",
            "license": "76569",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "3103641",
            "state": "MA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

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• Internal Medicine Physician in Southbridge, MA
• Providers in Southbridge, 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 Oct 2, 2025; 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.