Timothy Byun, MD
Hematology & Oncology · Orange, CANPI 1871545012
Payments from drug & device makers
What this record shows
The money is spread across several categories — speaking fees (39.2%), food and beverage and consulting fees — rather than concentrated in one kind of arrangement. 60 manufacturers reported payments, led by Merck at 30.8% of the total. Reporting peaked in 2019 at $45,858 and has fallen 87.8% since, to $5,583 in 2025. Among hematology & oncology clinicians in CA with any reported payments, this total sits in the top 10% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 1,574 payments — averaging $62.38 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Merck$30K
- E.r. Squibb & Sons, L.L.C.$23K
- AstraZeneca$12K
- Exelixis Inc.$5K
- Bristol Myers Squibb$5K
- Eisai Inc.$2K
- plus $20K from 54 others
Across 295 payments — averaging $9834.63 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.
- Gilead$1.3M
- Novartis$476K
- Genentech, Inc.$365K
- Merck$197K
- Partner Therapeutics, Inc.$138K
- Janssen Research & Development, LLC$85K
- plus $305K from 8 others
What the payments were for
- Consulting fees$24,03124%
- Speaking & faculty fees$38,47539%
- Travel & lodging$7,5928%
- Food & beverage$28,00129%
- Education$820%
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.
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.
How this compares
$98,180 in reported general payments places this provider in the 90th percentile of 1,363 hematology & oncology providers in California.
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 |
|---|---|---|
| XtandiEnzalutamide | 98 | $1,372,940 |
| RevlimidLenalidomide | 34 | $555,571 |
| IdhifaEnasidenib Mesylate | 13 | $445,462 |
| TagrissoOsimertinib Mesylate | 23 | $365,976 |
| NinlaroIxazomib Citrate | 23 | $323,596 |
| CabometyxCabozantinib S-Malate | 11 | $319,171 |
| SprycelDasatinib | 18 | $314,835 |
| KisqaliRibociclib Succinate | 16 | $265,142 |
| CalquenceAcalabrutinib Maleate | 17 | $195,436 |
| TasignaNilotinib Hcl | 11 | $173,456 |
| OrgovyxRelugolix | 41 | $111,809 |
| Abiraterone Acetate | 34 | $86,562 |
| Imatinib Mesylate | 35 | $77,401 |
| EliquisApixaban | 70 | $65,435 |
| CreonLipase/Protease/Amylase | 12 | $17,293 |
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 |
|---|---|---|
| Astellas Pharma US IncXtandi | $500 | $1,372,94098 claims |
| Bristol Myers SquibbRevlimid, Idhifa | $4,767 | $1,001,03347 claims |
| AstraZenecaTagrisso, Calquence | $12,420 | $561,41240 claims |
| NovartisKisqali, Tasigna | $1,572 | $438,59827 claims |
| Takeda Pharmaceuticals U.S.A., Inc.Ninlaro | $411 | $323,59623 claims |
| Exelixis Inc.Cabometyx | $5,128 | $319,17111 claims |
| E.r. Squibb & Sons, L.L.C.Sprycel | $22,708 | $314,83518 claims |
| Sumitomo Pharma America, Inc.Orgovyx | $273 | $111,80941 claims |
| Janssen Scientific Affairs, LLCAbiraterone Acetate | $1,090 | $86,56234 claims |
| PfizerEliquis | $1,665 | $65,43570 claims |
| AbbVieCreon | $824 | $17,29312 claims |
| Lilly USA, LLCOlanzapine | $121 | $4325 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 1,363 hematology & oncology providers in California.
Other hematology & oncology in Orange
- Catherine CoombsOrange$786K
- Arash Rezazadeh KalebastyOrange$516K
- Misako NagasakaOrange$507K
- Elizabeth BremOrange$335K
- May ChoOrange$334K
- Angela FleischmanOrange$255K
- Dennis SlamonLos Angeles$3.1M
- Sandra HorningStanford$2.5M
- Mohammadbagher ZiariCorona$2.5M
- George YaghmourLos Angeles$1.9M
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.