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NOLAN WILLIAMS
NPI 1811339641
Psychiatry & Neurology - Psychiatry in Napa, CA

Active since July 22, 2013PECOS Enrolled

NPPES record last updated: November 17, 2025. Verified against the NPPES registry weekly; last sync: August 09, 2026.

Record update history: Nov 17, 2025, May 16, 2023, Feb 22, 2022 (3 updates tracked since 2022).

About Nolan Williams NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

NOLAN WILLIAMS (NPI 1811339641) is an individual psychiatry provider in Napa, California, licensed in California (A159440) and active in the NPI registry since July 2013. He is enrolled in Medicare PECOS and maintains a secondary practice location in Ventura.

NPPES Registry Identity

NPI1811339641
Entity TypeIndividualMale
Primary Taxonomy2084P0800X
Provider Legal NameNOLAN WILLIAMS
Location Address1580 1ST STNapa, CA 94559-2841
Mailing AddressPo Box 412Green Mountain Falls, CO 80819-0412 · (316) 734-5280
Phone(707) 258-8757
Sole ProprietorNo
Enumeration DateJuly 22, 2013
Last NPPES UpdateNovember 17, 20253 updates tracked since enumeration
NPPES CertifiedNovember 17, 2025
✔ NPI 1811339641 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPsychiatry & Neurology · PsychiatryAllopathic & Osteopathic Physicians
Taxonomy Code2084P0800X
License✔ Licensed in CA · A159440
Definition
A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems.
1580 1ST ST, Napa, CA 94559
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Secondary Practice Location 1

Location 1200 Hillmont AveVentura, CA 93003-1647 · Phone (805) 652-6729

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Nolan Williams is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94559 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$192.16 typical visit price
range $65.08 – $192.16
Typical copayment $48.04 (range $16.27 – $48.04)
Most-billed visit code 99205
Established Patient
$80.32 typical visit price
range $21.86 – $157.83
Typical copayment $20.08 (range $5.46 – $39.45)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 12

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. JOHN ALEXANDER FORDHAM DO
Psychiatry & Neurology (Psychiatry)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757
QYANA KELLY GRIFFITH MD, MA
Psychiatry & Neurology (Psychiatry)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757
MERCY YARIELA PERDOMO RODRIGUEZ MD
Psychiatry & Neurology (Psychiatry)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757
ELIZABETH SHANE M.D.
Psychiatry & Neurology (Psychiatry)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757
DR. SIGURDUR O HEKTORSSON M.D.
Psychiatry & Neurology (Psychiatry)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757
DR. MICAH HOFFMAN MD
Psychiatry & Neurology (Psychiatry)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757
ROBERT JOHN HORON PHD
Psychologist (Clinical)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757
KATHERINE RACHEL ROBERTS MD
Psychiatry & Neurology (Psychiatry)
1580 1ST ST
NAPA, CA 94559
Napa County (707) 258-8757

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Nolan Williams's NPI number?

The NPI number for Nolan Williams is 1811339641. It was assigned to this individual provider in the NPPES registry on July 22, 2013.

Where is Nolan Williams located?

Nolan Williams practices at 1580 1st St, Napa, CA 94559. The listed phone number is (707) 258-8757.

What is Nolan Williams's specialty?

The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.

Is Nolan Williams enrolled in Medicare?

Yes. Nolan Williams is registered in the Medicare PECOS enrollment system.

When was this NPI record last updated?

The NPPES record for Nolan Williams was last updated on November 17, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 8 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.