Diane Nguyen, MD
NPI 1225065428 · Family Medicine Physician · Westminster, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Diane Nguyen, MD is a Family Medicine Physician provider in Westminster, CA (NPI 1225065428).
Provider details
- NPI number
- 1225065428
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- A84273 (CA)
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
19 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
308 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) |
|---|---|---|
| Chronic Care Management Services, First 20 Minutes of Clinical Staff Time Directed By Health Care Professional, Per Calendar Month99490 | 126 | $67 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 119 | $96 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 18 | $140 |
| Annual Depression Screening, 5 to 15 MinutesG0444 | 18 | $21 |
| Administration of Influenza Virus VaccineG0008 | 16 | $35 |
| Screening Mammography77067 | 11 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 55 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 218 | 74 |
| Amlodipine Besylate | 185 | 57 |
| Alendronate Sodium | 175 | 56 |
| Losartan Potassium | 91 | 33 |
| Omeprazole | 86 | 30 |
| Triamcinolone Acetonide | 74 | 29 |
| Metformin Hclbrand: Metformin Hcl Er |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$4,541 across 71 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
- 2006-06-26
- Last updated
- 2011-12-12
Frequently asked questions
- What is Diane Nguyen's NPI number?
- Diane Nguyen's National Provider Identifier (NPI) is 1225065428, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Diane Nguyen's specialty?
- Diane Nguyen is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Diane Nguyen located?
- Diane Nguyen's practice location on file with NPPES is 10362 Bolsa Avenue, Westminster, CA 92683-6763.
- What is Diane Nguyen's phone number?
- The practice phone number listed in the NPPES registry for Diane Nguyen is (714) 531-2091.
- Does Diane Nguyen accept Medicare?
- Diane Nguyen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Diane Nguyen's NPI active?
- Yes — Diane Nguyen's NPI (1225065428) is active in the NPPES registry as of the last update on 2011-12-12.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.