Gregory Roger Grenier, D.O
NPI 1134512593ActiveIndividual· Orthopaedic Surgery· Billings, MT
Orthopaedic Surgery (D.O) with Catholic Health Initiatives Colorado, practicing in Billings, Montana. 177 Medicare patients in 2024, $85,640 paid; all of their 118 Part D prescriptions were generic. Alliance Medical was the largest of 3 companies reporting payments in 2025, $197.43 in all, mostly food and beverage. Lists Mercy Regional Medical Center and 1 other hospital as hospital affiliations.
Overview
| NPI | 1134512593 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O |
| Sole proprietor | No |
| NPI issued | Mar 10, 2015 |
| Last updated in NPPES | Jan 6, 2023 |
| Certified by provider | Jan 6, 2023 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Orthopaedic Surgery Primary | 207X00000X | 98833 | MT |
| Orthopaedic Surgery | 207X00000X | DR.0070117 | CO |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Orthopedic Surgery (CO) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 177 |
|---|---|
| Services billed | 859 across 96 procedure codes |
| Paid by Medicare | $85,640 |
Part D prescriptions in 2024
| Prescriptions (claims) | 118 · 118 30-day fills |
|---|---|
| Patients | 50 |
| Total drug cost | $677.59 |
| Generic share | 100% of claims |
Education and affiliations
| Graduation year | 2015 |
|---|---|
| Medicare specialty | Orthopedic Surgery |
Medical group
- Catholic Health Initiatives ColoradoLakewood, CO · 1,225 clinicians
Hospital affiliations
- Mercy Regional Medical CenterDurango, CO
- San Juan Regional Medical Center IncFarmington, NM
Industry payments (Open Payments)
- 2025$197.43 · 6 payments from 3 companies
- 2024$1,172 · 7 payments from 5 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Alliance Medical | $104.80 | 3 |
| Biotissue Holdings Inc. | $61.41 | 2 |
| Stryker Corporation | $31.22 | 1 |
What the 2025 payments were for
- Food and Beverage$197.43 · 6 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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