Usama Mahmood, MD
Usama Mahmood, MD is a Radiation Oncology Physician in Fountain Valley, CA, registered under NPI 1386848844. 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 18111 BROOKHURST ST # LL0300, Fountain Valley, CA 92708. 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 |
|---|---|---|
| P035 | TX | Radiation Oncology Physician primary |
This provider holds licence P035 issued in TX. 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 - Radiation Oncology
- PAC ID
- 0648426882
Medicare enrolment is recorded as approved under the provider type Practitioner - Radiation Oncology. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Radiation Oncology covers
A radiologist who deals with the therapeutic applications of radiant energy and its modifiers and the study and management of disease, especially malignant tumors. NUCC Health Care Provider Taxonomy, code 2085R0001X
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 | 1386848844 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 11, 2007 |
| Last updated | Dec 6, 2016 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
18111 BROOKHURST ST # LL0300 Fountain Valley, CA 92708 (714) 962-7100 Fax (714) 963-7600 |
| Mailing address |
PO BOX 844945 Los Angeles, CA 90084 |
| Other identifiers |
301292401
(TX) |
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 | 8 | 6 | 8 | 4 | 8 | 8 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 3 | 7 | 6 | 7 | 4 | 7 | 8 | 8 |
Sum = 76 · next multiple of 10 = 80 · check digit = 4 · actual last digit = 4
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.