Stephen Yang, MD, DDS
Stephen Yang, MD, DDS is a provider specialising in Oral & Maxillofacial Surgery (D.M.D.) in San Francisco, CA, registered under NPI 1225775299. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 521 PARNASSUS AVE # 440, San Francisco, CA 94143. 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 |
|---|---|---|
| PTL15503 | CA | Oral & Maxillofacial Surgery (D.M.D.) primary |
| 109690 | CA | Oral and Maxillofacial Surgery (Dentist) |
This provider holds licence PTL15503 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 Oral & Maxillofacial Surgery covers
Oral and maxillofacial surgeons are trained to recognize and treat a wide spectrum of diseases, injuries and defects in the head, neck, face, jaws and the hard and soft tissues of the oral and maxillofacial region. They are also trained to administer anesthesia, and provide care in an office setting. They are trained to treat problems such as the extraction of wisdom teeth, misaligned jaws, tumors and cysts of the jaw and mouth, and to perform dental implant surgery. NUCC Health Care Provider Taxonomy, code 204E00000X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 204E00000X | Oral & Maxillofacial Surgery (D.M.D.) | PTL15503 | CA | primary |
| 1223S0112X | Oral and Maxillofacial Surgery (Dentist) Oral and Maxillofacial Surgery | 109690 | CA |
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 | 1225775299 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 19, 2022 |
| Last updated | Aug 27, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD, DDS |
| Practice address |
521 PARNASSUS AVE # 440 San Francisco, CA 94143 (415) 476-3242 |
| Mailing address |
513 PARNASSUS AVE # S321 San Francisco, CA 94143 |
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 | 2 | 2 | 5 | 7 | 7 | 5 | 2 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 2 | 4 | 5 | 5 | 7 | 1 | 2 | 9 |
Sum = 61 · next multiple of 10 = 70 · check digit = 9 · actual last digit = 9
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.