Diem Nguyen, O.D.
NPI 1669554812 · Optometrist · Easley, SC
Enrolled with Medicare as Practitioner - Optometry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Diem Nguyen, O.D. is a Optometrist provider in Easley, SC (NPI 1669554812).
Provider details
- NPI number
- 1669554812
- Entity type
- Individual
- Primary specialty
- OptometristEye and Vision Services Providers
- Credential
- O.D.
- Sex
- Female
- Sole proprietor
- No
- License
- 0618-001238 (VA)
Specialties & taxonomies
Eye and Vision Services Providers
Eye and Vision Services Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
919 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) |
|---|---|---|
| Established Patient Complete Exam of Visual System92014 | 354 | $115 |
| New Patient Complete Exam of Visual System92004 | 98 | $137 |
| Imaging of Retina92134 | 94 | $37 |
| Established Patient Problem Focused Exam of Visual System92012 | 81 | $81 |
| Imaging of Optic Nerve92133 | 79 | $32 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 76 | $120 |
| Exam of Visual Field With Extended Testing |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 6 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Tobramycin/Dexamethasonebrand: Tobramycin-Dexamethasone | 80 | 65 |
| Latanoprost | 70 | 33 |
| Cyclosporinebrand: Restasis | 47 | 18 |
| Cyclosporine | 25 | 18 |
| Neomycin/Polymyxin B/Dexamethabrand: Neomycin-Polymyxin-Dexameth | 14 | 12 |
| Dorzolamide Hcl/Timolol Maleatbrand: Dorzolamide-Timolol | 13 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they include 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 , 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.
$108 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
Additional practice locations (1)
- 601 Halton RdGreenville, SC 29607-3403Phone: (864) 458-7956Fax: (864) 458-8390
Registry dates
- Enumerated
- 2006-10-19
- Last updated
- 2025-09-22
- Certified
- 2025-09-22
Frequently asked questions
- What is Diem Nguyen's NPI number?
- Diem Nguyen's National Provider Identifier (NPI) is 1669554812, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Diem Nguyen's specialty?
- Diem Nguyen is listed in the NPPES registry with a primary specialty of Optometrist (Eye and Vision Services Providers).
- Where is Diem Nguyen located?
- Diem Nguyen's practice location on file with NPPES is 220 S Pendleton St, Easley, SC 29640-3048.
- What is Diem Nguyen's phone number?
- The practice phone number listed in the NPPES registry for Diem Nguyen is (864) 859-3233.
- Does Diem Nguyen accept Medicare?
- Diem Nguyen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Diem Nguyen's NPI active?
- Yes — Diem Nguyen's NPI (1669554812) is active in the NPPES registry as of the last update on 2025-09-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.