William Chen, LAC
William Chen, LAC is a provider specialising in Acupuncturist in San Mateo, CA, registered under NPI 1417013939. 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 30 S EL CAMINO REAL #111, 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 |
|---|---|---|
| AC9853 | CA | Acupuncturist primary |
This provider holds licence AC9853 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 Acupuncturist covers
An acupuncturist is a person who performs ancient therapy for alleviation of pain, anesthesia and treatment of some diseases. Acupuncturists use long, fine needles inserted into specific points in order to treat painful conditions or produce anesthesia. NUCC Health Care Provider Taxonomy, code 171100000X
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 | 1417013939 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Dec 29, 2006 |
| Last updated | Mar 5, 2012 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | LAC |
| Practice address |
30 S EL CAMINO REAL #111 San Mateo, CA 94401 (650) 235-6761 Fax (650) 685-8081 |
| Mailing address |
1220 SIXTH AVE STE A Belmont, CA 94002 |
| Other identifiers |
615659000
· FECA |
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 | 1 | 7 | 0 | 1 | 3 | 9 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 2 | 7 | 0 | 1 | 6 | 9 | 6 |
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.