Dirk Diefendorf, M.D.
Dirk Diefendorf, M.D. is a Sports Medicine (Neuromusculoskeletal Medicine) Physician in San Mateo, CA, registered under NPI 1467559443. 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 101 S ELLSWORTH AVE SUITE 607, San Mateo, CA 94401. 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 |
|---|---|---|
| G53558 | CA | Sports Medicine (Neuromusculoskeletal… primary |
This provider holds licence G53558 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 - Orthopedic Surgery
- PAC ID
- 0648462390
- Enrollment ID
- I20101013000318
Medicare enrolment is recorded as approved under the provider type Practitioner - Orthopedic Surgery. 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 Neuromusculoskeletal Medicine, Sports Medicine covers
A Neuromusculoskeletal Medicine and Osteopathic Manipulative Medicine physician trained to be responsible for the continuous care in the field of sports medicine encompasses increased knowledge and understanding of osteopathic principles and practice and heightened technical skills of osteopathic manipulative medicine and integrates each of these into the management of the individual engaged in physical exercise (sports) whether as an individual or in team participation. NUCC Health Care Provider Taxonomy, code 204C00000X
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 | 1467559443 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 20, 2006 |
| Last updated | Aug 30, 2010 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
101 S ELLSWORTH AVE SUITE 607 San Mateo, CA 94401 (650) 347-0157 Fax (650) 347-0566 |
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 | 4 | 6 | 7 | 5 | 5 | 9 | 4 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 3 | 7 | 1 | 5 | 9 | 4 | 8 |
Sum = 67 · next multiple of 10 = 70 · check digit = 3 · actual last digit = 3
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.