Mark Fagan, DDS
Mark Fagan, DDS is a provider specialising in Prosthodontics in Fort Drum, NY, registered under NPI 1588612790.
Getting there
The practice address on file is 10205 N RIVA RIDGE LOOP, Fort Drum, NY 13602. 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 |
|---|---|---|
| 11964 | MD | Prosthodontics primary |
This provider holds licence 11964 issued in MD. 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 Prosthodontics covers
That branch of dentistry pertaining to the restoration and maintenance of oral functions, comfort, appearance and health of the patient by the restoration of natural teeth and/or the replacement of missing teeth and contiguous oral and maxillofacial tissues with artificial substitutes. NUCC Health Care Provider Taxonomy, code 1223P0700X
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 | 1588612790 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 4, 2006 |
| Last updated | Apr 27, 2026 |
| Status | Active |
| Sole proprietor | No |
| Credential | DDS |
| Practice address |
10205 N RIVA RIDGE LOOP Fort Drum, NY 13602 (315) 772-5088 |
| Mailing address |
120 MILL CREEK LN Sackets Harbor, NY 13685 |
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 | 8 | 8 | 6 | 1 | 2 | 7 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 7 | 8 | 3 | 1 | 4 | 7 | 9 |
Sum = 70 · next multiple of 10 = 70 · check digit = 0 · actual last digit = 0
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.