Isabel Gay, DDS, MS
Isabel Gay, DDS, MS is a provider specialising in Periodontics in Alton, IL, registered under NPI 1518117548. 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 2800 COLLEGE AVE, Alton, IL 62002. 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 |
|---|---|---|
| 136000266 | IL | Periodontics primary |
This provider holds licence 136000266 issued in IL. 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 - Dentist
- PAC ID
- 3870896152
- Enrollment ID
- I20180625002345
Medicare enrolment is recorded as approved under the provider type Practitioner - Dentist. 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 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 | 1518117548 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 26, 2008 |
| Last updated | Oct 12, 2023 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Credential | DDS, MS |
| Practice address |
2800 COLLEGE AVE Alton, IL 62002 (618) 474-7397 Fax (618) 474-7124 |
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 | 1 | 8 | 1 | 1 | 7 | 5 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 2 | 8 | 2 | 1 | 5 | 5 | 8 |
Sum = 62 · next multiple of 10 = 70 · check digit = 8 · actual last digit = 8
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.