William Chen, M.D.
NPI 1881659142 · Internal Medicine Physician · Irvine, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Chen, M.D. is a Internal Medicine Physician provider in Irvine, CA (NPI 1881659142).
Provider details
- NPI number
- 1881659142
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A93575 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
20 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 · 31 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Furosemide | 240 | 100 |
| Losartan Potassium | 193 | 75 |
| Lisinopril | 142 | 53 |
| Amlodipine Besylate | 119 | 48 |
| Atorvastatin Calcium | 81 | 29 |
| Allopurinol | 77 | 33 |
| Metoprolol Tartrate | 72 | 30 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$102 across 1 record (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
- 2006-04-19
- Last updated
- 2021-12-01
Frequently asked questions
- What is William Chen's NPI number?
- William Chen's National Provider Identifier (NPI) is 1881659142, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Chen's specialty?
- William Chen is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Chen located?
- William Chen's practice location on file with NPPES is 6650 Alton Pkwy, Irvine, CA 92618-3734.
- What is William Chen's phone number?
- The practice phone number listed in the NPPES registry for William Chen is (949) 932-2514.
- Does William Chen accept Medicare?
- William Chen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Chen's NPI active?
- Yes — William Chen's NPI (1881659142) is active in the NPPES registry as of the last update on 2021-12-01.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.