Thomas Desmarais, MD
Thomas Desmarais, MD is a Vascular Surgery Physician in Billings, MT, registered under NPI 1972918639.
Getting there
The practice address on file is 1233 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 |
|---|---|---|
| MED-PHYS-LIC-76907 | MT | Vascular Surgery Physician primary |
This provider holds licence MED-PHYS-LIC-76907 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 - Vascular Surgery
- PAC ID
- 5496976912
Medicare enrolment is recorded as approved under the provider type Practitioner - Vascular Surgery. 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 Vascular Surgery covers
A surgeon with expertise in the management of surgical disorders of the blood vessels, excluding the intracranial vessels or the heart. NUCC Health Care Provider Taxonomy, code 2086S0129X
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 | 1972918639 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 21, 2014 |
| Last updated | Jun 24, 2019 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
1233 N 30TH ST Billings, MT 59101 (406) 657-7000 |
| Mailing address |
2900 12TH AVE N STE 400E Billings, MT 59101 |
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 | 9 | 7 | 2 | 9 | 1 | 8 | 6 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 9 | 5 | 2 | 9 | 1 | 7 | 6 | 6 |
Sum = 71 · next multiple of 10 = 80 · check digit = 9 · actual last digit = 9
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.