Individual provider Active NPI

Alanna Bridget Williams

  • Internal Medicine Physician
  • San Francisco, CA
National Provider Identifier
1407505613
Registry record updated Apr 24, 2025
On this page

Key facts

NPPES NPI Registry
Primary specialty
Internal Medicine PhysicianTaxonomy code 207R00000X
License
A189898 Issued in CA
Practice address
521 Parnassus Ave
San Francisco, CA 94143-2206
Phone
(415) 476-1000
NPI assigned
Mar 23, 2022
Last updated
Apr 24, 2025By the provider in NPPES
Sex
Female
Sole proprietor
Yes

NPPES NPI Registry

Updated by the provider on Apr 24, 2025

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

Specialties & licenses 2

Specialty (taxonomy)CodeLicenseStatePrimary
Student in an Organized Health Care Education/Training Program 390200000X NU
Internal Medicine Physician 207R00000X A189898 CA Primary

Addresses

Primary practice location

521 Parnassus Ave
San Francisco, CA 94143-2206

Mailing address

505 Parnassus Ave RM 1480
San Francisco, CA 94143-2204

Other practice location 1

505 Parnassus Ave
San Francisco, CA 94143-2204
Phone (415) 476-1000

Medicare participation

Medicare enrollment files
Medicare fee-for-service enrollment
Enrolled in CA
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

Enrollment IDStateProvider typePAC IDDetails
I20250502002505 CA Practitioner - Internal Medicine 2860925849 Reassigns benefits to 3 organizations

Care Compare profile

Medicare Care Compare
Specialty
Internal Medicine
Education
Washington University School of Medicine, 2022
Medicare assignment
Accepts the Medicare-approved amount as payment in full
Group practices

Practice addresses (Care Compare)

1701 Divisadero St
San Francisco, CA 94115-3011
Phone (415) 476-4029

505 Parnassus Ave
San Francisco, CA 94143-2204
Phone (415) 476-4029

Hospital & facility affiliations

National Provider Directory

National Provider Directory
Medicare enrollment (NPD)
Enrolled
Credentials
Doctor of Medicine

State licenses

LicenseStateTypeSpecialty
A189898CAMDInternal Medicine Physician

Practice roles

OrganizationSpecialtyStatusNew patients
UCSF Medical Group Business Services CurrentSince Apr 24, 2025 Accepting new patients
UCSF Medical Group Business Services Internal Medicine CurrentSince Apr 24, 2025 Accepting new patients
University of California San Francisco CurrentSince Apr 24, 2025 Accepting new patients
Regents of the University of California Internal Medicine CurrentSince Apr 24, 2025 Accepting new patients
University of California San Francisco CurrentSince Apr 24, 2025 Accepting new patients
University of California San Francisco Medical Center Past Accepting new patients
Regents of the University of California Past Accepting new patients

Locations

2330 Post St
San Francisco, CA 94115
Phone (415) 502-4444

400 Parnassus Ave
#A632
San Francisco, CA 94143
Phone (415) 473-1000

505 Parnassus Ave
San Francisco, CA 94143
Phone (415) 476-9058

505 Parnassus Ave
Rm 1480
San Francisco, CA 94143

505 Parnassus Ave
Rm M1480
San Francisco, CA 94143
Phone (415) 476-1528

521 Parnassus Ave
San Francisco, CA 94143
Phone (415) 476-9035

Organizations & group practices 7

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships, National Provider Directory roles and organizations whose NPPES authorized official is this provider.

Hospital & facility affiliations 2

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

NPI Registry JSON

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

{
    "created_epoch": "1647993600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1745452800000",
    "number": "1407505613",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "505 PARNASSUS AVE RM 1480",
            "city": "SAN FRANCISCO",
            "state": "CA",
            "postal_code": "941432204"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "521 PARNASSUS AVE",
            "city": "SAN FRANCISCO",
            "state": "CA",
            "postal_code": "941432206",
            "telephone_number": "415-476-1000"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "505 Parnassus Ave",
            "address_purpose": "LOCATION",
            "city": "San Francisco",
            "state": "CA",
            "postal_code": "941432204",
            "country_code": "US",
            "telephone_number": "415-476-1000",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "WILLIAMS",
        "first_name": "ALANNA",
        "middle_name": "BRIDGET",
        "sole_proprietor": "YES",
        "sex": "F",
        "enumeration_date": "2022-03-23",
        "last_updated": "2025-04-24",
        "certification_date": "2025-04-24",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "390200000X",
            "taxonomy_group": "",
            "desc": "Student in an Organized Health Care Education/Training Program",
            "state": "NU",
            "license": null,
            "primary": false
        },
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "CA",
            "license": "A189898",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

Other providers in San Francisco, CA

Sources for this page

Verify at the official NPI Registry.