Harold Hsu, M.D.
NPI 1770508111 · Internal Medicine Physician · Rosemead, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Harold Hsu, M.D. is a Internal Medicine Physician provider in Rosemead, CA (NPI 1770508111).
Provider details
- NPI number
- 1770508111
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- A 51859 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
2,016 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 1,445 | $99 |
| Insertion of Needle Into Vein for Collection of Blood Sample36415 | 184 | $9 |
| Subsequent Nursing Facility Care With Straightforward Level of Medical Decision Making, Per Day, If Using Time, 20 Minutes Or More99308 | 115 | $79 |
| Administration of Influenza Virus VaccineG0008 | 88 | $35 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 71 | $81 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 296 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 3,261 | 402 |
| Amlodipine Besylate | 2,115 | 268 |
| Telmisartan | 1,387 | 191 |
| Omeprazole | 1,265 | 160 |
| Olmesartan Medoxomil | 1,171 | 135 |
| Metoprolol Succinate | 1,038 | 128 |
| Rosuvastatin Calcium | 941 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$106 across 4 records (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
- 2006-07-13
- Last updated
- 2020-02-27
- Certified
- 2020-02-27
Frequently asked questions
- What is Harold Hsu's NPI number?
- Harold Hsu's National Provider Identifier (NPI) is 1770508111, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Harold Hsu's specialty?
- Harold Hsu is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Harold Hsu located?
- Harold Hsu's practice location on file with NPPES is 8622 Garvey Ave, Rosemead, CA 91770-3293.
- What is Harold Hsu's phone number?
- The practice phone number listed in the NPPES registry for Harold Hsu is (626) 280-6898.
- Does Harold Hsu accept Medicare?
- Harold Hsu is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Harold Hsu's NPI active?
- Yes — Harold Hsu's NPI (1770508111) is active in the NPPES registry as of the last update on 2020-02-27.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.