Greggory Gahn, MD
NPI 1720541147 · Retina Specialist (Ophthalmology) Physician · Reno, NV
Enrolled with Medicare as Practitioner - Ophthalmology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Greggory Gahn, MD is a Retina Specialist (Ophthalmology) Physician provider in Reno, NV (NPI 1720541147).
Provider details
- NPI number
- 1720541147
- Entity type
- Individual
- Primary specialty
- Retina Specialist (Ophthalmology) PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 23736 (NV)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
7 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
17 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Removal of Membrane of Retina With Removal of Internal Limiting Membrane of Retina67042 | 17 | $175 |
Typical Medicare-allowed amounts for these services range $175–$175 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 7 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Prednisolone Acetate | 228 | 106 |
| Dorzolamide Hcl/Timolol Maleatbrand: Dorzolamide-Timolol | 54 | 26 |
| Erythromycin Basebrand: Erythromycin | 31 | 23 |
| Brimonidine Tartrate | 19 | 12 |
| Neomycin/Polymyxin B/Dexamethabrand: Neomycin-Polymyxin-Dexameth | 17 | — |
| Timolol Maleate | 17 | — |
| Moxifloxacin Hclbrand: Moxifloxacin | 15 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$856 across 27 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2019-04-11
- Last updated
- 2025-10-03
- Certified
- 2025-10-03
Frequently asked questions
- What is Greggory Gahn's NPI number?
- Greggory Gahn's National Provider Identifier (NPI) is 1720541147, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Greggory Gahn's specialty?
- Greggory Gahn is listed in the NPPES registry with a primary specialty of Retina Specialist (Ophthalmology) Physician (Allopathic & Osteopathic Physicians).
- Where is Greggory Gahn located?
- Greggory Gahn's practice location on file with NPPES is 950 Ryland St, Reno, NV 89502-1605.
- What is Greggory Gahn's phone number?
- The practice phone number listed in the NPPES registry for Greggory Gahn is (757) 329-0286.
- Does Greggory Gahn accept Medicare?
- Greggory Gahn is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Greggory Gahn's NPI active?
- Yes — Greggory Gahn's NPI (1720541147) is active in the NPPES registry as of the last update on 2025-10-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.