Matthew Craig Williams, MD

Primary specialty

Child & Adolescent Psychiatry PhysicianTaxonomy code 2084P0804X

License

A186478 Issued in CA

Practice address

655 Redwood Hwy Frontage Rd Ste 261
Mill Valley, CA 94941-3011

Phone

(415) 381-1690

NPI assigned

Mar 29, 2021

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

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

Specialty

Psychiatry

Education

Georgetown University School of Medicine, 2021

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Bay Psychiatric AssociatesGroup PAC ID 6204723331, 60 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Alta Bates Summit Medical Center - Alta Bates Camp Hospital, Berkeley, CA, CCN 050305

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: mwilliams678378@hisp.ehr.sutterhealth.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.

• Bay Psychiatric Associates

  • Psychiatry Physician
  • Berkeley, CA
  • NPI 1427163229
  Medicare reassignment Care Compare group NPD

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

• Sutter Bay Hospitals

  • General Acute Care Hospital
  • Berkeley, CA
  • NPI 1639523004
  Care Compare affiliation

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

{
    "created_epoch": "1616976000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1780963200000",
    "number": "1326626797",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "655 REDWOOD HWY FRONTAGE RD STE 261",
            "city": "MILL VALLEY",
            "state": "CA",
            "postal_code": "949413011",
            "telephone_number": "415-381-1690"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "655 REDWOOD HWY FRONTAGE RD STE 261",
            "city": "MILL VALLEY",
            "state": "CA",
            "postal_code": "949413011",
            "telephone_number": "415-381-1690"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "WILLIAMS",
        "first_name": "MATTHEW",
        "middle_name": "CRAIG",
        "name_prefix": "Dr.",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2021-03-29",
        "last_updated": "2026-06-09",
        "certification_date": "2026-06-09",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "2084P0804X",
            "taxonomy_group": "",
            "desc": "Psychiatry & Neurology, Child & Adolescent Psychiatry",
            "state": "CA",
            "license": "A186478",
            "primary": true
        },
        {
            "code": "2084P0800X",
            "taxonomy_group": "",
            "desc": "Psychiatry & Neurology, Psychiatry",
            "state": "CA",
            "license": "A186478",
            "primary": false
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Jennifer Werba
• Sarah Gould Wescott, LMFT
• Mikela Wesson
• Leslie Whitaker, MA CCC-SLP
• Jade R Wienbar, ND
• Sofia Williams
• Heidi Wiltsee
• Tammy Ann Winchell, A.R.N.P
• Kristin A Wingfield Williams, M.D.
• Jessica Marian Wirth, PA-C

• Child & Adolescent Psychiatry Physician in Mill Valley, CA
• Providers in Mill Valley, CA by specialty
• Child & Adolescent Psychiatry Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jun 9, 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.