Tien-hsin Chang, D.D.S.
Tien-hsin Chang, D.D.S. is a provider specialising in Periodontics in Philadelphia, PA, registered under NPI 1558978957.
Getting there
The practice address on file is 240 S 40TH ST, Philadelphia, PA 19104. 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 |
|---|---|---|
| RFD000066 | PA | Periodontics primary |
This provider holds licence RFD000066 issued in PA. 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 | 1558978957 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 29, 2020 |
| Last updated | Oct 26, 2023 |
| Status | Deactivated |
| Sole proprietor | No |
| Credential | D.D.S. |
| Practice address |
240 S 40TH ST Philadelphia, PA 19104 (215) 898-8964 |
| Mailing address |
ONE KNEELAND STREET, 12 FLOOR, PERIODONTOLOGY CLINIC Boston, MA 02111 |
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 | 5 | 5 | 8 | 9 | 7 | 8 | 9 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 1 | 8 | 9 | 7 | 7 | 9 | 1 |
Sum = 73 · next multiple of 10 = 80 · check digit = 7 · actual last digit = 7
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.