Aman Chauhan, MD
Medical Oncology · San Francisco, CANPI 1902193147
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $62,109 of the $99,446 with a category attached, or 62.5%. 13 manufacturers reported payments, led by Exelixis Inc. at 28.9% of the total. 2025 is the largest year on record at $33,351, more than ten times the $2,619 reported in 2019.
Across 104 payments — averaging $956.21 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Exelixis Inc.$29K
- Boehringer Ingelheim$12K
- Curium US LLC$12K
- Tersera Therapeutics LLC$12K
- Ipsen Biopharmaceuticals, Inc$11K
- Lexicon Pharmaceuticals, Inc.$8K
- plus $17K from 7 others
Across 212 payments — averaging $23,912 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.
- Boehringer Ingelheim$2.4M
- Novartis$1.2M
- Alkermes, Inc.$1.1M
- Clovis Oncology, Inc.$127K
- E.r. Squibb & Sons, L.L.C.$78K
- Tersera Therapeutics LLC$54K
- plus $89K from 4 others
What the payments were for
- Consulting fees$62,10962%
- Speaking & faculty fees$24,08524%
- Travel & lodging$10,06010%
- Food & beverage$3,1923%
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 |
|---|---|---|
| Exelixis Inc. | 43 | $28,784 |
| Boehringer Ingelheim | 5 | $12,021 |
| Curium US LLC | 12 | $11,899 |
| Tersera Therapeutics LLC | 8 | $11,566 |
| Ipsen Biopharmaceuticals, Inc | 10 | $10,855 |
| Lexicon Pharmaceuticals, Inc. | 8 | $7,574 |
| Novartis | 8 | $5,137 |
| Sanofi | 3 | $4,143 |
| Lantheus Medical Imaging, Inc. | 2 | $2,880 |
| Advanced Accelerator Applications | 1 | $2,500 |
| Jazz Pharmaceuticals Inc. | 1 | $1,590 |
| Ipsen Innovation | 2 | $474 |
| Cardinal Health 414 LLC | 1 | $22 |
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
$99,446 in reported general payments places this provider in the 85th percentile of 379 medical 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 |
|---|---|---|
| Everolimus | 26 | $41,056 |
| Prochlorperazine Maleate | 16 | $303 |
| Dexamethasone | 17 | $138 |
| Methylprednisolone | 18 | $102 |
Paid to pharmacies, not to this prescriber.
Other medical oncology in San Francisco
- Stephen SherwinSan Francisco$6.9M
- John ParkSan Francisco$558K
- Kevin KimSan Francisco$176K
- Ana Velazquez MananaSan Francisco$90K
- Noam DrazinBeverly Hills$1.4M
- Farshid DayyaniOrange$1.2M
- April TeitelbaumSan Diego$1.1M
- Przemyslaw TwardowskiSanta Monica$995K
- Ann LowePalo Alto$923K
- Marin XavierSan Diego$919K
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.