Quick answers
- Does Gregory W. Rennirt accept Medicare assignment?
- Yes. Medicare's clinician data says Gregory W. Rennirt accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Gregory W. Rennirt see?
- In 2024, CMS data shows 13 Original Medicare patients and 18 services for Gregory W. Rennirt. This counts Original Medicare only and measures volume, not quality.
- What is Gregory W. Rennirt's NPI number?
- 1871517664. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Gregory W. Rennirt, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 13 |
|---|---|
| Services billed to Medicare | 18 |
| Different services or procedures | 8 |
| Participating Medicare provider | Yes |
| Average age of these patients | 76 |
Hospitals where Gregory W. Rennirt works
Medicare's Facility Affiliation Data lists Gregory W. Rennirt at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- CHI St Alexius Health WillistonWilliston, ND · Critical Access Hospital · Medicare rating: 3 of 5 stars · Emergency services: listed by Medicare · CCN 351334
Practice locations
Addresses where Gregory W. Rennirt is enrolled with Medicare (CMS data updated October 2, 2026).
- 1500 14th St W, Suite 300Williston, ND 58801 (701) 774‑7500
Group practices
Medicare enrollment lists Gregory W. Rennirt as a member of this group (CMS data updated October 2, 2026).
- Mercy Medical Center77 clinicians in the group
Specialties
- Orthopedic Surgeryprimary
Other orthopedic surgeons in North Dakota
Clinicians with the same Medicare primary specialty in North Dakota — not a recommendation.
Other clinicians in Mercy Medical Center
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Louisville School Of Medicine |
| Graduation year | 1992 (34 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1871517664 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians