Eugene Ahn, MD
Medical Oncology · Chicago, ILNPI 1093911307
Payments from drug & device makers
Across 505 payments — averaging $5588.17 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Merck$1.1M
- Novartis$887K
- Daiichi Sankyo Inc.$337K
- Genentech, Inc.$218K
- Incyte Corporation$153K
- Taiho Oncology, Inc.$76K
- plus $67K from 24 others
Across 1 payment — averaging $500.05 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.
- Eli Lilly$500
What the payments were for
- Food & beverage$1,78994%
- Education$1236%
Most of this is food and beverage — typically meals provided during product presentations at a clinic or hospital. Nationally that is the single largest category of reported payments by count.
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 |
|---|---|---|
| Merck | 158 | $1,083,737 |
| Novartis | 36 | $886,509 |
| Daiichi Sankyo Inc. | 77 | $337,268 |
| Genentech, Inc. | 24 | $217,981 |
| Incyte Corporation | 114 | $153,417 |
| Taiho Oncology, Inc. | 11 | $76,367 |
| Eli Lilly | 3 | $21,643 |
| Macrogenics, Inc. | 5 | $11,384 |
| Astrazeneca UK Limited | 2 | $10,548 |
| Puma Biotechnology, Inc. | 2 | $8,987 |
| E.r. Squibb & Sons, L.L.C. | 2 | $8,518 |
| Seagen Inc. | 4 | $4,359 |
| Amgen | 12 | $260 |
| Pfizer | 17 | $228 |
| Gilead | 6 | $191 |
| Lilly USA, LLC | 5 | $96 |
| EMD Serono, Inc. | 1 | $88 |
| Genentech USA, Inc. | 4 | $77 |
| Bristol Myers Squibb | 3 | $65 |
| Tactile Systems Technology Inc | 4 | $49 |
| Astellas Pharma US Inc | 3 | $49 |
| Bayer | 2 | $46 |
| AstraZeneca | 3 | $40 |
| R-pharm US LLC | 1 | $24 |
| Carl Zeiss Meditec, Inc. | 1 | $20 |
| Musculoskeletal Transplant Foundation Inc. | 1 | $20 |
| Exelixis Inc. | 1 | $15 |
| Eisai Inc. | 1 | $14 |
| Salix Pharmaceuticals, A Division Of Bausch Health US, LLC | 1 | $13 |
| Hoffmann-la Roche Limited | 1 | $12 |
How this compares
$2,822,028 in reported general payments places this provider in the 90th percentile of 144 medical 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 |
|---|---|---|
| IbrancePalbociclib | 13 | $194,279 |
| Letrozole | 29 | $500 |
| Tamoxifen Citrate | 42 | $403 |
| Anastrozole | 23 | $254 |
Paid to pharmacies, not to this prescriber.
Companies that both paid and supply prescribed drugs
These companies both reported payments to this provider and make drugs the provider prescribed under Medicare Part D in 2024. For most specialties this overlap is expected — a cardiologist who is paid by a cardiology drugmaker also treats heart disease. It is shown so the reader can see it, not because it implies anything on its own.
| Company | Paid to this provider | Part D cost of their drugs |
|---|---|---|
| PfizerIbrance | $228 | $194,27913 claims |
Reading this fairly. The Part D column is what drug plans and patients paid pharmacies — this provider received none of it, and it reflects how many patients they treat and what those drugs cost. Against peers, this provider's reported payments sit in the 90th percentile of 144 medical oncology providers in Illinois.
Other medical oncology in Chicago
- Andrzej JakubowiakChicago$42M
- Alexander PearsonChicago$9.3M
- Jyoti PatelChicago$7.5M
- Devalingam MahalingamChicago$7.1M
- Ardaman ShergillChicago$4.9M
- Sunandana ChandraChicago$4.6M
- William GradisharChicago$3.3M
- Manali BhaveChicago$3.3M
- Nisha MohindraChicago$2.4M
- Jeffrey SosmanChicago$2.3M
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.