Gregory Tierney, M.D.
NPI 1679519870 · Sports Medicine (Orthopaedic Surgery) Physician · Great Falls, MT
Enrolled with Medicare as Practitioner - Orthopedic Surgery · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gregory Tierney, M.D. is a Sports Medicine (Orthopaedic Surgery) Physician provider in Great Falls, MT (NPI 1679519870).
Provider details
- NPI number
- 1679519870
- Entity type
- Individual
- Primary specialty
- Sports Medicine (Orthopaedic Surgery) PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 7579 (MT)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
12 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 12 | $64 |
Typical Medicare-allowed amounts for these services range $64–$64 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-06-22
- Last updated
- 2024-04-05
- Certified
- 2022-12-08
Frequently asked questions
- What is Gregory Tierney's NPI number?
- Gregory Tierney's National Provider Identifier (NPI) is 1679519870, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gregory Tierney's specialty?
- Gregory Tierney is listed in the NPPES registry with a primary specialty of Sports Medicine (Orthopaedic Surgery) Physician (Allopathic & Osteopathic Physicians).
- Where is Gregory Tierney located?
- Gregory Tierney's practice location on file with NPPES is 1401 25th St S, Great Falls, MT 59405-5183.
- What is Gregory Tierney's phone number?
- The practice phone number listed in the NPPES registry for Gregory Tierney is (406) 731-8888.
- Does Gregory Tierney accept Medicare?
- Gregory Tierney is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gregory Tierney's NPI active?
- Yes — Gregory Tierney's NPI (1679519870) is active in the NPPES registry as of the last update on 2024-04-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.