William Castro, M.D.
NPI 1366607848 · Family Medicine Physician · Huntington Beach, CA
Enrolled with Medicare as Order and Referring Only - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Castro, M.D. is a Family Medicine Physician provider in Huntington Beach, CA (NPI 1366607848).
Provider details
- NPI number
- 1366607848
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A119270 (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
17 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 · 77 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 366 | 118 |
| Semaglutidebrand: Ozempic | 239 | 35 |
| Losartan Potassium | 233 | 68 |
| Metformin Hcl | 233 | 82 |
| Lisinopril | 153 | 47 |
| Gabapentin | 145 | 56 |
| Amlodipine Besylate |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$33 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
- 2008-07-23
- Last updated
- 2013-10-10
Frequently asked questions
- What is William Castro's NPI number?
- William Castro's National Provider Identifier (NPI) is 1366607848, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Castro's specialty?
- William Castro is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is William Castro located?
- William Castro's practice location on file with NPPES is 8041 Newman Ave, Huntington Beach, CA 92647-7034.
- What is William Castro's phone number?
- The practice phone number listed in the NPPES registry for William Castro is (714) 500-0228.
- Does William Castro accept Medicare?
- William Castro is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Castro's NPI active?
- Yes — William Castro's NPI (1366607848) is active in the NPPES registry as of the last update on 2013-10-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.