Joseph Hsiou, DDS
Joseph Hsiou, DDS is a provider specialising in Periodontics in South Pasadena, CA, registered under NPI 1689813735. 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 2130 HUNTINGTON DR 202, South Pasadena, CA 91030. 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 |
|---|---|---|
| 28005 | CA | Periodontics primary |
This provider holds licence 28005 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 Periodontics covers
That specialty of dentistry which encompasses the prevention, diagnosis and treatment of diseases of the supporting and surrounding tissues of the teeth or their substitutes and the maintenance of the health, function and esthetics of these structures and tissues. NUCC Health Care Provider Taxonomy, code 1223P0300X
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 | 1689813735 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Feb 12, 2009 |
| Last updated | Feb 12, 2009 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | DDS |
| Practice address |
2130 HUNTINGTON DR 202 South Pasadena, CA 91030 (626) 441-4511 Fax (626) 441-4512 |
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 | 6 | 8 | 9 | 8 | 1 | 3 | 7 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 7 | 9 | 7 | 1 | 6 | 7 | 6 |
Sum = 75 · next multiple of 10 = 80 · 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.