Olwen Hahn, MD
Hematology & Oncology · Chicago, ILNPI 1992823611
Payments from drug & device makers
Across 443 payments — averaging $26,917 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Pfizer$11.6M
- Seagen Inc.$135K
- Genentech, Inc.$83K
- Astrazeneca UK Limited$41K
- Daiichi Sankyo Inc.$32K
- F. Hoffmann-la Roche AG$28K
- plus $5K from 3 others
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| Pfizer | 366 | $11,599,890 |
| Seagen Inc. | 30 | $134,990 |
| Genentech, Inc. | 22 | $82,729 |
| Astrazeneca UK Limited | 12 | $40,911 |
| Daiichi Sankyo Inc. | 9 | $31,817 |
| F. Hoffmann-la Roche AG | 1 | $28,292 |
| Incyte Corporation | 1 | $5,276 |
| Genentech USA, Inc. | 1 | $157 |
| Gilead | 1 | $12 |
How this compares
$11,924,074 in reported general payments places this provider in the 95th percentile of 580 hematology & oncology providers in Illinois.
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Other hematology & oncology in Chicago
- Oana DanciuChicago$23.2M
- Shuo MaChicago$20.5M
- Christine BestvinaChicago$11.3M
- Russell SzmulewitzChicago$9.8M
- Randy SweisChicago$9.4M
- Hedy KindlerChicago$8.6M
- Reem KarmaliChicago$7.7M
- Wendy StockChicago$7.2M
- Justin KlineChicago$6.6M
- Jane WinterChicago$6.4M
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.