Michael Ishioka, M.D.
NPI 1811085400ActiveIndividual· Internal Medicine· Honolulu, HI
Internal Medicine (M.D.) in Honolulu, Hawaii, trained at University of Michigan Medical School (class of 1975). Their prescriptions cost Medicare Part D more than their services did: $479,589 for 4,567 claims, against $53,460 paid for services in 2024. Novo Nordisk Inc was the largest of 2 companies reporting payments in 2025, $133.92 in all, mostly food and beverage.
Overview
| NPI | 1811085400 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Oct 10, 2006 |
| Last updated in NPPES | Jul 8, 2007 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | MD-3260 | 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 - Internal Medicine (HI) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 285 |
|---|---|
| Services billed | 783 across 10 procedure codes |
| Paid by Medicare | $53,460 |
Part D prescriptions in 2024
| Prescriptions (claims) | 4,567 · 12,696 30-day fills |
|---|---|
| Patients | 490 |
| Total drug cost | $479,589 |
| Generic share | 89% of claims |
Education and affiliations
| Medical school | University of Michigan Medical School |
|---|---|
| Graduation year | 1975 |
| Medicare specialty | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Castle Medical CenterKailua, HI · 77 clinicians
Hospital affiliations
- Adventist Health CastleKailua, HI
- Kapiolani Medical Center for Women & ChildrenHonolulu, HI
- Kuakini Medical CenterHonolulu, HI
- Pali Momi Medical CenterAiea, HI
- The Queens Medical CenterHonolulu, HI
Other facilities
- Bayada Home Health CareHome health agency · Honolulu, HI
- Careresource HawaiiHome health agency · Honolulu, HI
- Home Health HonoluluHome health agency · Honolulu, HI
Industry payments (Open Payments)
- 2025$133.92 · 6 payments from 2 companies
- 2024$116.00 · 1 payment from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novo Nordisk Inc | $117.21 | 5 |
| Amgen Inc. | $16.71 | 1 |
What the 2025 payments were for
- Food and Beverage$117.65 · 5 payments
- Education$16.27 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 687 internal medicine physicians in Honolulu · All internal medicine physicians in Hawaii