William S. Loui, M.D.
NPI 1346217718ActiveIndividual· Internal Medicine, Hematology & Oncology· Honolulu, HI
Internal Medicine, Hematology & Oncology (M.D.) in Honolulu, Hawaii, trained at University of Hawaii John A. Burns School of Medicine (class of 1989). Their prescriptions cost Medicare Part D more than their services did: $3,579,029 for 1,075 claims, against $111,237 paid for services in 2024. Novartis Pharmaceuticals Corporation was the largest of 36 companies reporting payments in 2025, $2,929 in all, mostly food and beverage.
Overview
| NPI | 1346217718 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Mar 3, 2006 |
| Last updated in NPPES | Mar 31, 2021 |
| Certified by provider | Mar 31, 2021 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Hematology & Oncology Primary | 207RH0003X | MD10912 | HI |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Hematology/Oncology (HI) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 402 |
|---|---|
| Services billed | 1,477 across 15 procedure codes |
| Paid by Medicare | $111,237 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,075 · 1,827 30-day fills |
|---|---|
| Patients | 216 |
| Total drug cost | $3,579,029 |
| Generic share | 75% of claims |
Education and affiliations
| Medical school | University of Hawaii John A. Burns School of Medicine |
|---|---|
| Graduation year | 1989 |
| Medicare specialty | Hematology/Oncology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Castle Medical CenterKailua, HI · 77 clinicians
Hospital affiliations
- Adventist Health CastleKailua, HI
- Kahuku Medical CenterKahuku, HI
- Kuakini Medical CenterHonolulu, HI
- Straub Clinic and HospitalHonolulu, HI
- The Queens Medical CenterHonolulu, HI
Industry payments (Open Payments)
- 2025$2,929 · 131 payments from 36 companies
- 2024$1,639 · 54 payments from 22 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novartis Pharmaceuticals Corporation | $399.00 | 16 |
| Astrazeneca Pharmaceuticals LP | $327.21 | 25 |
| Alexion Pharmaceuticals, Inc. | $228.41 | 7 |
| Janssen Biotech, Inc. | $221.66 | 7 |
| Genentech USA, Inc. | $169.11 | 10 |
What the 2025 payments were for
- Food and Beverage$2,730 · 129 payments
- Education$198.95 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 34 hematologist-oncologists in Honolulu · All hematologist-oncologists in Hawaii