Gregory Riddle, MD
Gregory Riddle, MD is an Aerospace Medicine Physician in Grand Forks Afb, ND, registered under NPI 1043398456. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty. 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 1599 JONES STREET, Grand Forks Afb, ND 58205. 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 |
|---|---|---|
| 19406 | AL | Aerospace Medicine Physician primary |
| 19406 | AL | Family Medicine Physician |
| 19406 | AL | Sports Medicine (Family Medicine)… |
This provider holds licence 19406 issued in AL. 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 - Family Practice
- PAC ID
- 0648213454
Medicare enrolment is recorded as approved under the provider type Practitioner - Family Practice. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Aerospace Medicine covers
Aerospace medicine focuses on the clinical care, research, and operational support of the health, safety, and performance of crewmembers and passengers of air and space vehicles, together with the support personnel who assist operation of such vehicles. This population often works and lives in remote, isolated, extreme, or enclosed environments under conditions of physical and psychological stress. Practitioners strive for an optimal human-machine match in occupational settings rich with environmental hazards and engineering countermeasures. NUCC Health Care Provider Taxonomy, code 2083A0100X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 2083A0100X | Aerospace Medicine Physician Aerospace Medicine | 19406 | AL | primary |
| 207Q00000X | Family Medicine Physician | 19406 | AL | |
| 207QS0010X | Sports Medicine (Family Medicine) Physician Sports Medicine | 19406 | AL |
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 | 1043398456 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Nov 2, 2006 |
| Last updated | Dec 8, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
1599 JONES STREET Grand Forks Afb, ND 58205 (701) 747-5326 |
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 | 0 | 4 | 3 | 3 | 9 | 8 | 4 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 8 | 3 | 6 | 9 | 7 | 4 | 1 |
Sum = 64 · next multiple of 10 = 70 · check digit = 6 · actual last digit = 6
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.