William Nguyen, M.D.
NPI 1043424575 · Internal Medicine Physician · Orange, CA
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Nguyen, M.D. is a Internal Medicine Physician provider in Orange, CA (NPI 1043424575).
Provider details
- NPI number
- 1043424575
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- A98370 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
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 · 17 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Omeprazole | 207 | 94 |
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-C | 202 | 198 |
| Pantoprazole Sodium | 95 | 47 |
| Colestipol Hcl | 39 | 16 |
| Sucralfate | 23 | — |
| Lubiprostone | 23 | — |
| Mercaptopurine | 22 | — |
| Mesalamine |
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-05-10
- Last updated
- 2021-11-04
- Certified
- 2021-11-04
Frequently asked questions
- What is William Nguyen's NPI number?
- William Nguyen's National Provider Identifier (NPI) is 1043424575, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Nguyen's specialty?
- William Nguyen is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Nguyen located?
- William Nguyen's practice location on file with NPPES is 101 the City Dr S Bldg 200, Orange, CA 92868-3201.
- What is William Nguyen's phone number?
- The practice phone number listed in the NPPES registry for William Nguyen is (408) 826-2362.
- Does William Nguyen accept Medicare?
- William Nguyen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Nguyen's NPI active?
- Yes — William Nguyen's NPI (1043424575) is active in the NPPES registry as of the last update on 2021-11-04.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.