Michael Grunstein

Primary specialty

Student in an Organized Health Care Education/Training ProgramTaxonomy code 390200000X

Practice address

20 York St
New Haven, CT 06510-3220

Phone

(203) 688-4242

NPI assigned

Jun 17, 2021

Sex

Male

Sole proprietor

Yes

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

Specialties & licenses 1

Addresses

Medicare fee-for-service enrollment

Enrolled in CT

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

Medicare enrollment (NPD)

Enrolled

Interoperability endpoints

• Direct secure messaging: mgrunstein715258@direct.ynhh.org

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

{
    "created_epoch": "1623888000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1755648000000",
    "number": "1255909941",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "20 YORK ST",
            "city": "NEW HAVEN",
            "state": "CT",
            "postal_code": "065103220",
            "telephone_number": "203-688-4242"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "20 YORK ST",
            "city": "NEW HAVEN",
            "state": "CT",
            "postal_code": "065103220",
            "telephone_number": "203-688-4242"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "707 E. Main Medical Center",
            "address_purpose": "LOCATION",
            "city": "Middletown",
            "state": "NY",
            "postal_code": "10940",
            "country_code": "US",
            "telephone_number": "453-337-3738",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "300 Community Dr",
            "address_purpose": "LOCATION",
            "city": "Manhasset",
            "state": "NY",
            "postal_code": "110303816",
            "country_code": "US",
            "telephone_number": "516-562-0100",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "GRUNSTEIN",
        "first_name": "MICHAEL",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2021-06-17",
        "last_updated": "2025-08-20",
        "certification_date": "2025-08-20",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "390200000X",
            "taxonomy_group": "",
            "desc": "Student in an Organized Health Care Education/Training Program",
            "state": null,
            "license": null,
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Peter J Gruber, M.D,. PH.D
• Jeffrey R Gruen, MD
• Stephanie Grullon, RN
• Victoria Grumbles, MD
• Laurie Blum Grunebaum, PH.D.
• Jennifer Grzybinski, APRN
• Brett Gu
• Chan Gu, MD
• Sean Xiang Gu, MD, PHD
• Cindy Frances Guandalini, APRN

• Student in an Organized Health Care Education/Training Program in New Haven, CT
• Providers in New Haven, CT by specialty
• Student in an Organized Health Care Education/Training Program in Connecticut

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Aug 20, 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.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.