Amitabha Mazumder, MD
Hematology & Oncology · Downey, CANPI 1881682318
Payments from drug & device makers
What this record shows
This record is dominated by speaking fees: $141,240 of the $206,999 with a category attached, or 68.2%. It is spread thinly across 60 manufacturers, the largest accounting for just 18.4%. Reporting peaked in 2019 at $84,897 and has fallen 92.3% since, to $6,517 in 2025. Among hematology & oncology clinicians in CA with any reported payments, this total sits in the top 5% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 1,107 payments — averaging $186.99 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Takeda Pharmaceuticals U.S.A., Inc.$38K
- Karyopharm Therapeutics Inc.$34K
- Amgen$31K
- Johnson & Johnson$28K
- E.r. Squibb & Sons, L.L.C.$18K
- Incyte Corporation$17K
- plus $40K from 54 others
Across 137 payments — averaging $22,041 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.
- Merck$1.5M
- Novartis$903K
- E.r. Squibb & Sons, L.L.C.$188K
- Janssen Research & Development, LLC$149K
- Bristol Myers Squibb$132K
- Karyopharm Therapeutics Inc.$55K
- plus $109K from 4 others
What the payments were for
- Consulting fees$30,32115%
- Speaking & faculty fees$141,24068%
- Travel & lodging$10,8125%
- Food & beverage$23,28911%
- Education$580%
- Other$1,2801%
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
$206,999 in reported general payments places this provider in the 95th 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 |
|---|---|---|
| VerzenioAbemaciclib | 35 | $478,744 |
| XtandiEnzalutamide | 33 | $448,969 |
| RevlimidLenalidomide | 27 | $428,459 |
| PomalystPomalidomide | 22 | $399,092 |
| IbrancePalbociclib | 23 | $370,937 |
| CalquenceAcalabrutinib Maleate | 23 | $256,644 |
| EnhertuFam-Trastuzumab Deruxtecn-Nxki | 26 | $229,683 |
| NinlaroIxazomib Citrate | 13 | $169,322 |
| OrgovyxRelugolix | 59 | $149,144 |
| Lenalidomide | 13 | $146,915 |
| Abiraterone Acetate | 56 | $94,154 |
| ProcritEpoetin Alfa | 15 | $37,302 |
| XareltoRivaroxaban | 33 | $21,346 |
| EliquisApixaban | 32 | $19,126 |
| Exemestane | 38 | $6,661 |
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 |
|---|---|---|
| Lilly USA, LLCVerzenio, Olanzapine | $379 | $478,87452 claims |
| Astellas Pharma US IncXtandi | $371 | $448,96933 claims |
| Bristol Myers SquibbRevlimid | $10,699 | $428,45927 claims |
| E.r. Squibb & Sons, L.L.C.Pomalyst | $18,254 | $399,09222 claims |
| PfizerIbrance, Eliquis | $1,226 | $390,06355 claims |
| AstraZenecaCalquence | $1,575 | $256,64423 claims |
| Daiichi Sankyo Inc.Enhertu | $266 | $229,68326 claims |
| Takeda Pharmaceuticals U.S.A., Inc.Ninlaro | $38,088 | $169,32213 claims |
| Sumitomo Pharma America, Inc.Orgovyx | $57 | $149,14459 claims |
| Janssen Scientific Affairs, LLCAbiraterone Acetate | $614 | $94,15456 claims |
| Johnson & JohnsonProcrit, Xarelto | $27,990 | $58,64848 claims |
| Teva Pharmaceuticals USA, Inc.Acyclovir | $47 | $9921 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 95th percentile of 1,363 hematology & oncology providers in California.
Other hematology & oncology in Downey
- Dennis SlamonLos Angeles$3.1M
- Sandra HorningStanford$2.5M
- Mohammadbagher ZiariCorona$2.5M
- George YaghmourLos Angeles$1.9M
- Robert VescioWest Hollywood$1.1M
- Kevin KellyLos Angeles$894K
- Johnny ChangEncino$884K
- Nitin RohatgiSacramento$814K
- Omid HamidSanta Monica$809K
- Catherine CoombsOrange$786K
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.