William Grant Day, M.D.

Primary specialty

Allergy & Immunology PhysicianTaxonomy code 207K00000X

License

0101271195 Issued in VA

Practice address

620 John Paul Jones Cir Ste 275
Portsmouth, VA 23708-2197

Phone

(757) 953-2000

NPI assigned

Jan 31, 2019

Last updated

Jun 30, 2026By the provider in NPPES

Sex

Male

Sole proprietor

Yes

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

Specialties & licenses 2

Addresses

Electronic endpoints 1

Medicare fee-for-service enrollment

Enrolled in VA

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

Credentials

Doctor of Medicine

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

{
    "created_epoch": "1548892800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1782777600000",
    "number": "1740745041",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "620 JOHN PAUL JONES CIR",
            "city": "PORTSMOUTH",
            "state": "VA",
            "postal_code": "237082111",
            "telephone_number": "757-953-2194"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "620 JOHN PAUL JONES CIR STE 275",
            "city": "PORTSMOUTH",
            "state": "VA",
            "postal_code": "237082197",
            "telephone_number": "757-953-2000"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "DAY",
        "first_name": "WILLIAM",
        "middle_name": "GRANT",
        "name_prefix": "Dr.",
        "credential": "M.D.",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2019-01-31",
        "last_updated": "2026-06-30",
        "certification_date": "2026-06-30",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207K00000X",
            "taxonomy_group": "",
            "desc": "Allergy & Immunology",
            "state": "VA",
            "license": "0101271195",
            "primary": true
        },
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "VA",
            "license": "0101271195",
            "primary": false
        }
    ],
    "identifiers": [],
    "endpoints": [
        {
            "endpointType": "DIRECT",
            "endpointTypeDescription": "Direct Messaging Address",
            "endpoint": "william.g.day26.mil@health.mil",
            "affiliation": "N",
            "endpointDescription": "Encrypted E-mail",
            "use": "DIRECT",
            "useDescription": "Direct",
            "contentType": "CSV",
            "contentTypeDescription": "CSV",
            "address_1": "620 John Paul Jones Cir",
            "city": "Portsmouth",
            "state": "VA",
            "country_code": "US",
            "postal_code": "237082111",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "other_names": []
}

• Jimmy Dawood, MD
• Rehan Dawood, D.O.
• Allegrah C Day, RN
• Justin Lee Day, D.O.
• Rhonda Day, CRNA
• Beth Michelle Days, RPH
• DB Leak Inc
• Erwin De Guia
• 04Gloria Villanueva De la Cruz, M.D.
• Ana Laura De la Paz Martinez

• Allergy & Immunology Physician in Portsmouth, VA
• Providers in Portsmouth, VA by specialty
• Allergy & Immunology Physician in Virginia

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jun 30, 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.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.