Joel Geffin, M.D.
Joel Geffin, M.D. is a Cornea and External Diseases Specialist Physician in Waterbury, CT, registered under NPI 1659341675. 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 1201 W MAIN ST SUITE 100, Waterbury, CT 06708. 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 |
|---|---|---|
| 033778 | CT | Cornea and External Diseases Specialist… primary |
| 033778 | CT | Ophthalmology Physician |
This provider holds licence 033778 issued in CT. 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 - Ophthalmology
- PAC ID
- 5092869404
- Enrollment ID
- I20101117000246
Medicare enrolment is recorded as approved under the provider type Practitioner - Ophthalmology. 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 Cornea and External Diseases Specialist covers
An ophthalmologist who specializes in diseases of the cornea, sclera, eyelids, conjunctiva, and anterior segment of the eye. NUCC Health Care Provider Taxonomy, code 207WX0120X
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 | |
|---|---|---|---|---|
| 207WX0120X | Cornea and External Diseases Specialist Physician Cornea and External Diseases Specialist | 033778 | CT | primary |
| 207W00000X | Ophthalmology Physician | 033778 | CT |
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 | 1659341675 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jan 23, 2006 |
| Last updated | Jun 26, 2024 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
1201 W MAIN ST SUITE 100 Waterbury, CT 06708 (203) 597-9100 Fax (203) 596-4758 |
| Other identifiers |
180000936
· Other (CT) |
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 | 5 | 9 | 3 | 4 | 1 | 6 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 1 | 9 | 6 | 4 | 2 | 6 | 5 |
Sum = 65 · next multiple of 10 = 70 · 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.