Naoky C. Tsai, MD
NPI 1245214618ActiveIndividual· Internal Medicine, Gastroenterology· Kailua, HI
Internal Medicine, Gastroenterology (MD) with Castle Medical Center, practicing in Kailua, Hawaii. Their prescriptions cost Medicare Part D more than their services did: $679,322 for 595 claims, against $40,479 paid for services in 2024. Madrigal Pharmaceuticals was the largest of 17 companies reporting payments in 2025, $155,198 in all, mostly speaking and faculty fees. Lists Adventist Health Castle and 3 other hospitals as hospital affiliations.
Overview
| NPI | 1245214618 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | Yes |
| NPI issued | Nov 30, 2005 |
| Last updated in NPPES | Oct 30, 2007 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 3796 | HI |
| Internal Medicine, Hepatology | 207RI0008X | 3796 | 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 - Gastroenterology (HI) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 202 |
|---|---|
| Services billed | 417 across 16 procedure codes |
| Paid by Medicare | $40,479 |
Part D prescriptions in 2024
| Prescriptions (claims) | 595 · 1,441 30-day fills |
|---|---|
| Patients | 136 |
| Total drug cost | $679,322 |
| Generic share | 75% of claims |
Education and affiliations
| Graduation year | 1974 |
|---|---|
| Medicare specialty | Gastroenterology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Castle Medical CenterKailua, HI · 77 clinicians
Hospital affiliations
- Adventist Health CastleKailua, HI
- Pali Momi Medical CenterAiea, HI
- Straub Clinic and HospitalHonolulu, HI
- The Queens Medical CenterHonolulu, HI
Industry payments (Open Payments)
- 2025$155,198 · 208 payments from 17 companies
- 2024$102,973 · 169 payments from 23 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Madrigal Pharmaceuticals | $98,210 | 83 |
| Ipsen Biopharmaceuticals, Inc | $28,623 | 17 |
| Gilead Sciences, Inc. | $24,236 | 43 |
| Echosens North America, Inc. | $1,512 | 2 |
| Abbvie Inc. | $829.73 | 14 |
What the 2025 payments were for
- Compensation for services other than consulting, including serving as faculty or as a speaker at a venue other than a continuing education program$118,896 · 30 payments
- Travel and Lodging$27,141 · 32 payments
- Food and Beverage$9,097 · 144 payments
- Education$64.54 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other Internal Medicine, Gastroenterology providers in Kailua
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All Internal Medicine, Gastroenterology providers in Hawaii →