David Williams, MD
David Williams, MD is a Cardiovascular Disease Physician in Vallejo, CA, registered under NPI 1922186816.
Getting there
The practice address on file is 975 SERENO DR, Vallejo, CA 94589. 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 |
|---|---|---|
| G17557 | CA | Cardiovascular Disease Physician primary |
This provider holds licence G17557 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
- Order And Referring Only - Internal Medicine
- PAC ID
- 5496041261
- Enrollment ID
- I20160902000183
Medicare enrolment is recorded as approved under the provider type Order And Referring Only - Internal Medicine. 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 Cardiovascular Disease covers
An internist who specializes in diseases of the heart and blood vessels and manages complex cardiac conditions such as heart attacks and life-threatening, abnormal heartbeat rhythms. NUCC Health Care Provider Taxonomy, code 207RC0000X
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 | 1922186816 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 1, 2006 |
| Last updated | Jul 8, 2007 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
975 SERENO DR Vallejo, CA 94589 (707) 651-1000 |
| Mailing address |
1800 HARRISON ST FL 7 Oakland, CA 94612 |
| Other identifiers |
00G175570
· Medicaid (CA) |
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 | 9 | 2 | 2 | 1 | 8 | 6 | 8 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 9 | 4 | 2 | 2 | 8 | 3 | 8 | 2 |
Sum = 64 · next multiple of 10 = 70 · check digit = 6 · actual last digit = 6
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.