Erin Duncan, OD
NPI 1821191222 · Optometrist · San Dimas, CA
Enrolled with Medicare as Practitioner - Optometry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Erin Duncan, OD is a Optometrist provider in San Dimas, CA (NPI 1821191222).
Provider details
- NPI number
- 1821191222
- Entity type
- Individual
- Primary specialty
- OptometristEye and Vision Services Providers
- Credential
- OD
- Sex
- Female
- Sole proprietor
- No
- License
- 12152TPA (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 tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 · 4 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Latanoprost | 140 | 34 |
| Timolol Maleate | 31 | — |
| Brimonidine Tartrate | 11 | — |
| Cyclosporine | 11 | — |
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
- 2006-09-07
- Last updated
- 2022-09-07
- Certified
- 2022-09-07
Frequently asked questions
- What is Erin Duncan's NPI number?
- Erin Duncan's National Provider Identifier (NPI) is 1821191222, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Erin Duncan's specialty?
- Erin Duncan is listed in the NPPES registry with a primary specialty of Optometrist (Eye and Vision Services Providers).
- Where is Erin Duncan located?
- Erin Duncan's practice location on file with NPPES is 1255 W Arrow Hwy, San Dimas, CA 91773-2340.
- What is Erin Duncan's phone number?
- The practice phone number listed in the NPPES registry for Erin Duncan is (909) 394-5380.
- Does Erin Duncan accept Medicare?
- Erin Duncan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Erin Duncan's NPI active?
- Yes — Erin Duncan's NPI (1821191222) is active in the NPPES registry as of the last update on 2022-09-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.