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DR. ROBERT C WILLIAMS DDS
NPI 1336268077
Dentist - General Practice in Angwin, CA

Active since March 27, 2007PECOS EnrolledAccepts Medicare Assignment
41 ANGWIN PLAZA, ANGWIN, CA 94508(707) 965-2479(707) 965-0427 Get Directions Write a Review

NPPES record last updated: July 8, 2007. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Dr. Robert C Williams Dds NPPES

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

DR. ROBERT C WILLIAMS DDS (NPI 1336268077) is an individual general practice provider in Angwin, California, licensed in California (21293) and active in the NPI registry since March 2007. He is enrolled in Medicare PECOS and is a graduate of Loma Linda University School Of Dentistry (1970).

NPPES Registry Identity

NPI1336268077
Entity TypeIndividualMale
Primary Taxonomy1223G0001X
Provider Legal NameDR. ROBERT C WILLIAMSCredential: DDS
Location Address41 ANGWIN PLAZAAngwin, CA 94508
Mailing Address3212 Jefferson St., Suite 196Napa, CA 94558 · (707) 255-8825 · Fax (707) 252-9325
Phone(707) 965-2479
Fax(707) 965-0427
Sole ProprietorNo
Medical School CMSLoma Linda University School Of DentistryGraduated 1970
Enumeration DateMarch 27, 2007
Last NPPES UpdateJuly 8, 2007
✔ NPI 1336268077 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyDentist · General PracticeDental Providers
Taxonomy Code1223G0001X
License✔ Licensed in CA · 21293
Definition
A general dentist is the primary dental care provider for patients of all ages. The general dentist is responsible for the diagnosis, treatment, management and overall coordination of services related to patients' oral health needs.
41 ANGWIN PLAZA, Angwin, CA 94508
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Robert C Williams Dds is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID8022292127
PECOS Enrollment IDI20110818000628
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.

Medicare Billing Reassignment

Medicare enrollment records show Robert Williams reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Newberry Dentistry Inc.
19 mi
General Practice
3220 BEARD RD STE A
Napa, CA 94558
  • Reassigned Medicare billing, California enrollment
  • 3 clinicians in this Medicare group
NPI 1194533083 (707) 255-2832

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203
This service involves an initial office or outpatient visit for a new patient. The healthcare professional will spend 30-44 minutes understanding your health history, current issues, and discussing possible treatment plans. It's a comprehensive evaluation to start your healthcare journey.
12 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94508 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
$98.97 typical visit price
range $65.08 – $192.16
Typical copayment $24.74 (range $16.27 – $48.04)
Most-billed visit code 99203
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 2

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

ROBERT C. WILLIAMS, DDS, INC
Dentist
41 ANGWIN PLAZA
ANGWIN, CA 94508
Napa County (707) 965-2479
PETER E VANDENHOVEN DDS
Dentist (General Practice)
41 ANGWIN PLAZA
ANGWIN, CA 94508
Napa County (707) 965-2479

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 Robert Williams's NPI number?

The NPI number for Robert Williams is 1336268077. It was assigned to this individual provider in the NPPES registry on March 27, 2007.

Where is Robert Williams located?

Robert Williams practices at 41 Angwin Plaza, Angwin, CA 94508. The listed phone number is (707) 965-2479.

What is Robert Williams's specialty?

The primary specialty registered for this NPI is Dentist, specializing in General Practice, with taxonomy code 1223G0001X.

Is Robert Williams enrolled in Medicare?

Yes. Robert Williams is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organization bills Medicare for Robert Williams's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Robert Williams reassigns Medicare benefits to Newberry Dentistry Inc. (Napa, CA). The 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 Robert 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 Robert Williams was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 years 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.