James Mack, MD
James Mack, MD is an Endocrinology, Diabetes & Metabolism Physician in Billings, MT, registered under NPI 1669575445.
Getting there
The practice address on file is 1045 N 30TH ST, Billings, MT 59101. 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 |
|---|---|---|
| 8739 | MT | Endocrinology, Diabetes & Metabolism… primary |
This provider holds licence 8739 issued in MT. 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 - Endocrinology
- PAC ID
- 8426090010
Medicare enrolment is recorded as approved under the provider type Practitioner - Endocrinology. 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 Endocrinology, Diabetes & Metabolism covers
An internist who concentrates on disorders of the internal (endocrine) glands such as the thyroid and adrenal glands. This specialist also deals with disorders such as diabetes, metabolic and nutritional disorders, obesity, pituitary diseases and menstrual and sexual problems. NUCC Health Care Provider Taxonomy, code 207RE0101X
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 | 1669575445 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 6, 2006 |
| Last updated | Feb 10, 2022 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
1045 N 30TH ST Billings, MT 59101 (406) 238-2500 |
| Mailing address |
PO BOX 35100 Billings, MT 59107 |
| Other identifiers |
00000833
· BCBS PIN (MT) 114711100 · MDCD PIN (WY) 0019975 · MDCD PIN (MT) |
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 | 6 | 9 | 5 | 7 | 5 | 4 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 3 | 9 | 1 | 7 | 1 | 4 | 8 |
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.