NOLAN WILLIAMS
NPI 1811339641
Psychiatry & Neurology - Psychiatry in Napa, CA
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
Specialties & Licenses
Secondary Practice Location 1
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Nolan Williams is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
8Medicare enrollment records show Nolan Williams reassigns Medicare billing to 8 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Santa Rosa, CA 95401
- Reassigned Medicare billing, California enrollment
- Medicare enrollment name: Traditions Psychiatry Group PC
- 98 clinicians in this Medicare group
Oakland, CA 94602
- Reassigned Medicare billing, California enrollment
- 900 clinicians in this Medicare group
Palo Alto, CA 94306
- Reassigned Medicare billing, California enrollment
- 2,460 clinicians in this Medicare group
Eureka, CA 95501
- Reassigned Medicare billing, California enrollment
- 65 clinicians in this Medicare group
Santa Maria, CA 93458
- Reassigned Medicare billing, California enrollment
- Medicare enrollment name: Santa Barbara County Auditor
- 100 clinicians in this Medicare group
Ventura, CA 93001
- Reassigned Medicare billing, California enrollment
- 710 clinicians in this Medicare group
Philipsburg, PA 16866
- Reassigned Medicare billing, Pennsylvania enrollment
- 4,429 clinicians in this Medicare group
Moosic, PA 18507
- Reassigned Medicare billing, Pennsylvania enrollment
- 27 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
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.
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.
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.
Which organizations bill Medicare for Nolan Williams's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Nolan Williams reassigns Medicare benefits to 8 organizations: Traditions Psychiatry Group, P.C (Santa Rosa, CA), Alameda Health System (Oakland, CA), County Of Santa Clara (Palo Alto, CA), County Of Humboldt (Eureka, CA), Santa Barbara County Department Of Behavioral Wellness (Santa Maria, CA) and 3 more organizations, listed in the Medicare section above. Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Nolan Williams's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
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 11 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.
# Nolan Williams · NPI 1811339641
Psychiatry physician in Napa, California. Individual provider, active in the CMS NPPES registry since July 22, 2013.
## Identity
- **NPI:** 1811339641 (Entity type: Individual)
- **Enumerated:** July 22, 2013
- **Primary specialty:** Psychiatry & Neurology - Psychiatry · taxonomy 2084P0800X
- **State license:** A159440 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 1580 1ST ST, Napa, CA 94559-2841
- **Phone:** (707) 258-8757
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 8 organizations under Medicare reassignment (form CMS-855R): Traditions Psychiatry Group, P.C (NPI 1083802979, Santa Rosa, CA); Alameda Health System (NPI 1740332931, Oakland, CA); County Of Santa Clara (NPI 1285228080, Palo Alto, CA); County Of Humboldt (NPI 1033300306, Eureka, CA); Santa Barbara County Department Of Behavioral Wellness (NPI 1467707331, Santa Maria, CA); and 3 more · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** November 17, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1811339641) · Data from the CMS NPPES public registry.