John Ayers, MD
Hematology & Oncology · Warrenville, ILNPI 1477540821
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $1,650 of the $1,996 with a category attached, or 82.7%. AstraZeneca accounts for 90.6% of it on its own, with 5 other manufacturers making up the rest. Reporting peaked in 2024 at $1,742 and has fallen 96.1% since, to $68 in 2025. That places this record below the midpoint for hematology & oncology clinicians in IL, where the typical reported total is $2,365.
Across 8 payments — averaging $249.47 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- AstraZeneca$2K
- GE HealthCare$135
- Sysmex America, Inc.$22
- E.r. Squibb & Sons, L.L.C.$16
- Gilead$12
- Pfizer$3
Across 14 payments — averaging $3170.40 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$20K
- Tolmar, Inc.$18K
- Merck$7K
What the payments were for
- Consulting fees$1,65083%
- Food & beverage$24912%
- Education$965%
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 |
|---|---|---|
| AstraZeneca | 3 | $1,808 |
| GE HealthCare | 1 | $135 |
| Sysmex America, Inc. | 1 | $22 |
| E.r. Squibb & Sons, L.L.C. | 1 | $16 |
| Gilead | 1 | $12 |
| Pfizer | 1 | $3 |
How this compares
$1,996 in reported general payments places this provider in the 45th 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 |
|---|---|---|
| VerzenioAbemaciclib | 20 | $304,257 |
| PromactaEltrombopag Olamine | 12 | $87,707 |
| EliquisApixaban | 76 | $83,627 |
| XareltoRivaroxaban | 27 | $31,545 |
| Tamoxifen Citrate | 255 | $6,494 |
| Raloxifene Hcl | 124 | $6,078 |
| Letrozole | 126 | $3,522 |
| Exemestane | 22 | $2,543 |
| Anastrozole | 121 | $2,115 |
| Hydroxyurea | 20 | $452 |
| Dexamethasone | 14 | $321 |
| Prochlorperazine Maleate | 42 | $317 |
| Gabapentin | 12 | $307 |
| Ondansetron OdtOndansetron | 14 | $208 |
| Prednisone | 12 | $65 |
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 |
|---|---|---|
| PfizerEliquis | $3 | $83,62776 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 45th percentile of 580 hematology & oncology providers in Illinois.
Other hematology & oncology in Warrenville
- Mohamad Khair KhasawnehMaywood$998K
- Michael BishopChicago$974K
- Jamile ShammoChicago$910K
- John BerryBerwyn$687K
- Young Kwang ChaeChicago$563K
- Irfan MirzaChicago$544K
- Marina GarassinoChicago$397K
- Tulio RodriguezZion$337K
- Chih-Yi LiaoChicago$317K
- Gary KayElk Grove Village$314K
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.