Robert Williams, DDS
Robert Williams, DDS is a provider specialising in General Practice Dentistry in Angwin, CA, registered under NPI 1336268077.
Getting there
The practice address on file is 41 ANGWIN PLAZA, Angwin, CA 94508. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 21293 | CA | General Practice Dentistry primary |
This provider holds licence 21293 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Oral Surgery
- PAC ID
- 8022292127
Enrolled in Medicare 2 times, across 1 state:
| State | Enrollment ID | Provider type |
|---|---|---|
| California | I20110818000628 | Practitioner - Oral Surgery |
| California | O20170125001352 | Dme Supplier - Oral Surgery - Dentist |
Medicare enrolment is recorded as approved under the provider type Practitioner - Oral Surgery. There are 2 separate enrolment records. Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What General Practice covers
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. NUCC Health Care Provider Taxonomy, code 1223G0001X
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1336268077 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 27, 2007 |
| Last updated | Jul 8, 2007 |
| Status | Active |
| Sole proprietor | No |
| Credential | DDS |
| Practice address |
41 ANGWIN PLAZA Angwin, CA 94508 (707) 965-2479 Fax (707) 965-0427 |
| Mailing address |
3212 JEFFERSON ST. SUITE 196 Napa, CA 94558 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 3 | 3 | 6 | 2 | 6 | 8 | 0 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 3 | 6 | 6 | 4 | 6 | 7 | 0 | 5 |
Sum = 63 · next multiple of 10 = 70 · check digit = 7 · actual last digit = 7
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.