Warren Hsiao, MD
NPI 1316095391 · Internal Medicine Physician · Harbor City, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Warren Hsiao, MD is a Internal Medicine Physician provider in Harbor City, CA (NPI 1316095391).
Provider details
- NPI number
- 1316095391
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A55179 (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 · 90 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 656 | 214 |
| Rosuvastatin Calcium | 645 | 213 |
| Amlodipine Besylate | 526 | 186 |
| Losartan Potassium | 385 | 120 |
| Lisinopril | 274 | 90 |
| Levothyroxine Sodium | 212 | 67 |
| Atenolol |
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-01-08
- Last updated
- 2021-11-18
Frequently asked questions
- What is Warren Hsiao's NPI number?
- Warren Hsiao's National Provider Identifier (NPI) is 1316095391, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Warren Hsiao's specialty?
- Warren Hsiao is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Warren Hsiao located?
- Warren Hsiao's practice location on file with NPPES is 25825 Vermont Ave, Harbor City, CA 90710-3518.
- What is Warren Hsiao's phone number?
- The practice phone number listed in the NPPES registry for Warren Hsiao is (310) 325-5111.
- Does Warren Hsiao accept Medicare?
- Warren Hsiao is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Warren Hsiao's NPI active?
- Yes — Warren Hsiao's NPI (1316095391) is active in the NPPES registry as of the last update on 2021-11-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.