Olwen Hahn, MD
Hematology & Oncology · Chicago, ILNPI 1992823611
Payments from drug & device makers
What this record shows
The money is spread across several categories — consulting fees (53.3%), travel and lodging and food and beverage — rather than concentrated in one kind of arrangement. 5 manufacturers reported payments, led by Seagen Inc. at 53.3% of the total. Reporting peaked in 2020 at $2,190 and has fallen 92.8% since, to $157 in 2025.
Across 15 payments — averaging $273.86 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Seagen Inc.$2K
- Astrazeneca UK Limited$2K
- Genentech USA, Inc.$157
- Pfizer$12
- Gilead$12
Across 428 payments — averaging $27,850 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.
- Pfizer$11.6M
- Seagen Inc.$133K
- Genentech, Inc.$83K
- Astrazeneca UK Limited$39K
- Daiichi Sankyo Inc.$32K
- F. Hoffmann-la Roche AG$28K
- plus $5K from 1 others
What the payments were for
- Consulting fees$2,19053%
- Travel & lodging$1,11827%
- Food & beverage$77619%
- Education$241%
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 |
|---|---|---|
| Seagen Inc. | 1 | $2,190 |
| Astrazeneca UK Limited | 11 | $1,737 |
| Genentech USA, Inc. | 1 | $157 |
| Pfizer | 1 | $12 |
| Gilead | 1 | $12 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
- TUKYSA$2,190
How this compares
$4,108 in reported general payments places this provider in the 55th 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.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| KisqaliRibociclib Succinate | 24 | $274,342 |
| VerzenioAbemaciclib | 17 | $259,296 |
| Exemestane | 26 | $6,777 |
| Anastrozole | 133 | $2,325 |
| Tamoxifen Citrate | 24 | $483 |
| Letrozole | 20 | $307 |
| Prochlorperazine Maleate | 15 | $135 |
| Ondansetron Hcl | 14 | $112 |
Paid to pharmacies, not to this prescriber.
Other hematology & oncology in Chicago
- Michael BishopChicago$974K
- Jamile ShammoChicago$910K
- Young Kwang ChaeChicago$563K
- Irfan MirzaChicago$544K
- Marina GarassinoChicago$397K
- Chih-Yi LiaoChicago$317K
- Rita NandaChicago$286K
- Shuo MaChicago$280K
- Santosh SarafChicago$275K
- Peter RiedellChicago$273K
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.