Thomas Gross, M.D.
Thomas Gross, M.D. is an Emergency Medicine Physician in Vallejo, CA, registered under NPI 1174745525. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is EMERGENCY DEPT., KAISER PERMANENTE MEDICAL CENTER 675 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 |
|---|---|---|
| G65532 | CA | Emergency Medicine Physician primary |
This provider holds licence G65532 issued in CA. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Emergency Medicine covers
An emergency physician focuses on the immediate decision making and action necessary to prevent death or any further disability both in the pre-hospital setting by directing emergency medical technicians and in the emergency department. The emergency physician provides immediate recognition, evaluation, care, stabilization and disposition of a generally diversified population of adult and pediatric patients in response to acute illness and injury. NUCC Health Care Provider Taxonomy, code 207P00000X
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 | 1174745525 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 3, 2007 |
| Last updated | May 31, 2026 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
EMERGENCY DEPT., KAISER PERMANENTE MEDICAL CENTER 675 SERENO DR Vallejo, CA 94589 (707) 651-4910 |
| Mailing address |
9636 CHERRY RIDGE RD Sebastopol, CA 95472 |
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 | 1 | 7 | 4 | 7 | 4 | 5 | 5 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 5 | 4 | 5 | 4 | 1 | 5 | 4 |
Sum = 55 · next multiple of 10 = 60 · check digit = 5 · actual last digit = 5
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.