Nancy Guenthner, O.D.
NPI 1639335128 · Optometrist · Round Rock, TX
Enrolled with Medicare as Practitioner - Optometry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Nancy Guenthner, O.D. is a Optometrist provider in Round Rock, TX (NPI 1639335128).
Provider details
- NPI number
- 1639335128
- Entity type
- Individual
- Primary specialty
- OptometristEye and Vision Services Providers
- Credential
- O.D.
- Sex
- Female
- Sole proprietor
- No
- License
- 7212TG (TX)
Specialties & taxonomies
Eye and Vision Services Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
17 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
1 documented practice location
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
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 prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Latanoprost | 23 |
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.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$227 across 5 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
- 2008-08-04
- Last updated
- 2022-06-27
- Certified
- 2022-06-27
Frequently asked questions
- What is Nancy Guenthner's NPI number?
- Nancy Guenthner's National Provider Identifier (NPI) is 1639335128, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Nancy Guenthner's specialty?
- Nancy Guenthner is listed in the NPPES registry with a primary specialty of Optometrist (Eye and Vision Services Providers).
- Where is Nancy Guenthner located?
- Nancy Guenthner's practice location on file with NPPES is 17261 Smyers Ln Ste 100, Round Rock, TX 78681-2496.
- What is Nancy Guenthner's phone number?
- The practice phone number listed in the NPPES registry for Nancy Guenthner is (512) 501-2100.
- Does Nancy Guenthner accept Medicare?
- Nancy Guenthner is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Nancy Guenthner's NPI active?
- Yes — Nancy Guenthner's NPI (1639335128) is active in the NPPES registry as of the last update on 2022-06-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.