Willaim Allen Decker, PH. D.

Primary specialty

Cognitive & Behavioral PsychologistTaxonomy code 103TB0200X

License

0810002331 Issued in VA

Practice address

1423 Powhatan St
Suite 8
Alexandria, VA 22314-1389

Phone

(703) 836-3678

Fax

(703) 836-2667

NPI assigned

Mar 20, 2007

Sex

Male

Sole proprietor

Yes

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

Specialties & licenses 4

Addresses

Other identifiers 1

Medicare fee-for-service enrollment

Enrolled in DC

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: No
• Power mobility devices: No
• Hospice: No

Green means eligible to order or refer.

Enrollment records 1

Specialty

Clinical Psychologist

Education

Other, 1975

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Telehealth

Offers telehealth services

Practice addresses (Care Compare)

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Philosophy

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

{
    "created_epoch": "1174348800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1757548800000",
    "number": "1033234950",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1423 POWHATAN ST",
            "address_2": "SUITE 7",
            "city": "ALEXANDRIA",
            "state": "VA",
            "postal_code": "223141389",
            "telephone_number": "703-836-3678",
            "fax_number": "703-836-2667"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1423 POWHATAN ST",
            "address_2": "SUITE 8",
            "city": "ALEXANDRIA",
            "state": "VA",
            "postal_code": "223141389",
            "telephone_number": "703-836-3678",
            "fax_number": "703-836-2667"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "DECKER",
        "first_name": "WILLAIM",
        "middle_name": "ALLEN",
        "name_prefix": "Dr.",
        "credential": "PH. D.",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2007-03-20",
        "last_updated": "2025-09-11",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "103G00000X",
            "taxonomy_group": "",
            "desc": "Clinical Neuropsychologist",
            "state": "VA",
            "license": "0810002331",
            "primary": false
        },
        {
            "code": "103TB0200X",
            "taxonomy_group": "",
            "desc": "Psychologist, Cognitive & Behavioral",
            "state": "VA",
            "license": "0810002331",
            "primary": true
        },
        {
            "code": "103TC0700X",
            "taxonomy_group": "",
            "desc": "Psychologist, Clinical",
            "state": "VA",
            "license": "0810002331",
            "primary": false
        },
        {
            "code": "103TH0100X",
            "taxonomy_group": "",
            "desc": "Psychologist, Health Service",
            "state": "VA",
            "license": "0810002331",
            "primary": false
        }
    ],
    "identifiers": [
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "BCBS NCA CAREFIRST",
            "identifier": "A7860001",
            "state": "MD"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Lauren Elizabeth Deangelis, CRNA
• Daniel J Deary, CRNA
• Gina Deblasio, PA-C
• Mary Debolt, DPT
• Russell Anthony Decarlo, DDS
• Monique Jeanne Deely, LCSW
• Imani Deen, LPC
• Saffie Deen, LPN
• Jemeg V Dees, LPC
• Define Physical Therapy, LLC

• Cognitive & Behavioral Psychologist in Alexandria, VA
• Providers in Alexandria, VA by specialty
• Cognitive & Behavioral Psychologist in Virginia

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Sep 11, 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.