Gregory Wingren, O.D.
NPI 1164857140 · Optometrist · Napa, CA
Enrolled with Medicare as Practitioner - Optometry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gregory Wingren, O.D. is a Optometrist provider in Napa, CA (NPI 1164857140).
Provider details
- NPI number
- 1164857140
- Entity type
- Individual
- Primary specialty
- OptometristEye and Vision Services Providers
- Credential
- O.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 14767 (CA)
Specialties & taxonomies
Eye and Vision Services Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
12 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
48 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 Complete Exam of Visual System92014 | 25 | $150 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 23 | $104 |
Typical Medicare-allowed amounts for these services range $104–$150 (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 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Timolol Maleate | 15 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2013-09-09
- Last updated
- 2014-02-24
Frequently asked questions
- What is Gregory Wingren's NPI number?
- Gregory Wingren's National Provider Identifier (NPI) is 1164857140, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gregory Wingren's specialty?
- Gregory Wingren is listed in the NPPES registry with a primary specialty of Optometrist (Eye and Vision Services Providers).
- Where is Gregory Wingren located?
- Gregory Wingren's practice location on file with NPPES is 895 Trancas St, Napa, CA 94558-3040.
- What is Gregory Wingren's phone number?
- The practice phone number listed in the NPPES registry for Gregory Wingren is (707) 252-2020.
- Does Gregory Wingren accept Medicare?
- Gregory Wingren is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gregory Wingren's NPI active?
- Yes — Gregory Wingren's NPI (1164857140) is active in the NPPES registry as of the last update on 2014-02-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.