William Chen, DO
NPI 1538654355 · Family Medicine Physician · Ventura, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Chen, DO is a Family Medicine Physician provider in Ventura, CA (NPI 1538654355).
Provider details
- NPI number
- 1538654355
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Male
- Sole proprietor
- No
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Student, Health Care
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
8 yrs in NPPES registry
- Profile completeness25% of score
83% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
69 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) |
|---|---|---|
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 35 | $9 |
| Hemoglobin A1c Level83036 | 22 | $10 |
| Blood Test, Lipids (cholesterol and Triglycerides)80061 | 12 | $13 |
Typical Medicare-allowed amounts for these services range $9–$13 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 11 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Amlodipine Besylate | 36 | 12 |
| Atorvastatin Calcium | 33 | 15 |
| Losartan Potassium | 30 | 11 |
| Metformin Hcl | 30 | — |
| Empagliflozinbrand: Jardiance | 23 | — |
| Lisinopril | 21 | — |
| Pioglitazone Hcl |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$120 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
- 2018-06-25
- Last updated
- 2021-05-23
- Certified
- 2021-05-23
Frequently asked questions
- What is William Chen's NPI number?
- William Chen's National Provider Identifier (NPI) is 1538654355, 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 Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Chen located?
- William Chen's practice location on file with NPPES is 147 N Brent St, Ventura, CA 93003-2809.
- What is William Chen's phone number?
- The practice phone number listed in the NPPES registry for William Chen is (805) 652-5672.
- 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 (1538654355) is active in the NPPES registry as of the last update on 2021-05-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.