Gene Z. Chiao, MD
NPI 1699733188ActiveIndividual· Internal Medicine· Northbrook, IL
Opted out of Medicare from June 2024 to June 2028. Internal Medicine (MD) in Northbrook, Illinois, licensed in IL, with an NPI issued in May 2006. Part D covered 339 prescriptions written in 2024, 87% of them generic. Abbvie Inc. was the largest of 24 companies reporting payments in 2025, $3,734 in all, mostly food and beverage.
Overview
| NPI | 1699733188 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | May 3, 2006 |
| Last updated in NPPES | Sep 26, 2025 |
| Certified by provider | Sep 26, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | 036-079891 | IL |
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) | Not in the public enrollment file of Oct 1, 2026 |
|---|---|
| Opt-out | Opted out Jun 3, 2024 – Jun 3, 2028 |
| Can order and refer | Yes |
During an opt-out period the provider sees Medicare patients only under private contracts, and Medicare does not pay claims for their services.
Part D prescriptions in 2024
| Prescriptions (claims) | 339 · 669 30-day fills |
|---|---|
| Patients | 112 |
| Total drug cost | $167,318 |
| Generic share | 87% of claims |
Industry payments (Open Payments)
- 2025$3,734 · 162 payments from 24 companies
- 2024$3,480 · 148 payments from 23 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $696.69 | 34 |
| Janssen Biotech, Inc. | $466.55 | 23 |
| Madrigal Pharmaceuticals | $369.95 | 9 |
| Takeda Pharmaceuticals U.S.A., Inc. | $293.66 | 14 |
| Lilly USA, LLC | $245.86 | 10 |
What the 2025 payments were for
- Food and Beverage$3,734 · 162 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 49 internal medicine physicians in Northbrook · All internal medicine physicians in Illinois