Michael Harris Nathanson, MD

Primary specialty

Gastroenterology PhysicianTaxonomy code 207RG0100X

License

029365 Issued in CT

Practice address

15 York St
New Haven, CT 06510-3221

Phone

(203) 785-4138

Fax

(203) 737-1345

NPI assigned

Nov 25, 2005

Sex

Male

Sole proprietor

No

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

Specialties & licenses 2

Addresses

Other identifiers 2

Medicare fee-for-service enrollment

Enrolled in CT, FL2 enrollments

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 2

Specialty

Internal MedicineAlso: Gastroenterology

Education

Other, 1985

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Yale UniversityGroup PAC ID 9436061736, 2,632 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Bridgeport Hospital Hospital, Bridgeport, CT, CCN 070010
• Yale-New Haven Hospital Hospital, New Haven, CT, CCN 070022

Merit-based Incentive Payment System (MIPS)

Final score

87.36 of 100Reported as group

Quality

77.36

Promoting interoperability

100

Improvement activities

40

Cost

74.27

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: mnathanson8477@direct.ynhh.org

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.

• Yale University

  • Anesthesiology Physician
  • New Haven, CT
  • NPI 1205822236
  Medicare reassignment Care Compare group NPD
• Gi Diagnostics, LLC

  • Gastroenterology Physician
  • Boca Raton, FL
  • NPI 1396500633
  Medicare reassignment Authorized official
• Bridgeport Hospital

  • General Acute Care Hospital
  • Bridgeport, CT
  • NPI 1649260845
  Medicare reassignment NPD
• Bridgeport Hospital

  • General Acute Care Hospital
  • Milford, CT
  • NPI 1891376810
  NPD
• Yale University

  • Durable Medical Equipment & Medical Supplies
  • Fairfield, CT
  • NPI 1548066962
  NPD

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

• Bridgeport Hospital

  • General Acute Care Hospital
  • Bridgeport, CT
  • NPI 1649260845
  Care Compare affiliation
• Bridgeport Hospital

  • General Acute Care Hospital
  • Bridgeport, CT
  • NPI 1992910152
  Care Compare affiliation
• Yale New Haven Hospital

  • General Acute Care Hospital
  • New Haven, CT
  • NPI 1336139500
  Care Compare affiliation
• Yale New Haven Hospital

  • General Acute Care Hospital
  • New Haven, CT
  • NPI 1578778726
  Care Compare affiliation

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

{
    "created_epoch": "1132876800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1775088000000",
    "number": "1437132230",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "15 YORK ST",
            "address_2": "LMP - 180",
            "city": "NEW HAVEN",
            "state": "CT",
            "postal_code": "065103221",
            "telephone_number": "203-785-4138",
            "fax_number": "203-737-1345"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "15 YORK ST",
            "city": "NEW HAVEN",
            "state": "CT",
            "postal_code": "065103221",
            "telephone_number": "203-785-4138",
            "fax_number": "203-737-1345"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "4805 NW 2nd Ave",
            "address_purpose": "LOCATION",
            "city": "Boca Raton",
            "state": "FL",
            "postal_code": "334314141",
            "country_code": "US",
            "telephone_number": "561-961-0208",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "NATHANSON",
        "first_name": "MICHAEL",
        "middle_name": "HARRIS",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2005-11-25",
        "last_updated": "2026-04-02",
        "certification_date": "2026-04-02",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RG0100X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Gastroenterology",
            "state": "CT",
            "license": "029365",
            "primary": true
        },
        {
            "code": "207RG0100X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Gastroenterology",
            "state": "FL",
            "license": "ME158547",
            "primary": false
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "001293654",
            "state": "CT"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "129020000",
            "state": "FL"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Noureen Nassra, PA-C
• Harshdeep Singh Nat, M.D.
• Rosy Nat
• Eesha Vijaykumar Natarajan, MBBS
• Viswa B Nathan, M.D.
• Claudelle Natividad Le, CRNA
• Varidhi Nauriyal
• Gustavo Nava, LCSW
• Jonathan Naval
• Dhasakumar S Navaratnam, MD

• Gastroenterology Physician in New Haven, CT
• Providers in New Haven, CT by specialty
• Gastroenterology Physician in Connecticut

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Apr 2, 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.