Yvonne Chen, MD
Nephrology · Oakland, CANPI 1306959135
Payments from drug & device makers
Across 326 payments — averaging $34.51 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Otsuka Pharmaceutical Development & Commercialization, Inc.$3K
- Otsuka America Pharmaceutical, Inc.$1K
- AstraZeneca$1K
- Fresenius USA Marketing, Inc.$818
- Amgen$776
- Travere Therapeutics, Inc.$560
- plus $3K from 19 others
What the payments were for
- Consulting fees$2,98427%
- Speaking & faculty fees$6005%
- Travel & lodging$550%
- Food & beverage$7,49467%
- Education$1161%
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 |
|---|---|---|
| Otsuka Pharmaceutical Development & Commercialization, Inc. | 10 | $3,313 |
| Otsuka America Pharmaceutical, Inc. | 49 | $1,269 |
| AstraZeneca(2 entities) | 48 | $1,238 |
| Fresenius USA Marketing, Inc. | 47 | $818 |
| Amgen(2 entities) | 37 | $776 |
| Travere Therapeutics, Inc. | 30 | $560 |
| Sanofi | 2 | $425 |
| Lilly USA, LLC | 8 | $335 |
| Vifor Pharma, Inc. | 5 | $291 |
| Mallinckrodt Hospital Products Inc. | 10 | $277 |
| Novo Nordisk | 14 | $263 |
| Boehringer Ingelheim | 9 | $253 |
| Calliditas Therapeutics US Inc. | 9 | $231 |
| Bayer | 9 | $206 |
| GSK | 5 | $192 |
| ANI Pharmaceuticals, Inc. | 6 | $167 |
| Novartis | 6 | $153 |
| OPKO Pharmaceuticals, LLC | 5 | $101 |
| Aurinia Pharma U.S., Inc. | 4 | $97 |
| Ardelyx, Inc. | 3 | $87 |
| Daiichi Sankyo Inc. | 4 | $63 |
| Johnson & Johnson | 2 | $44 |
| Akebia Therapeutics Inc | 2 | $39 |
| Apellis Pharmaceuticals, Inc. | 1 | $27 |
| Nxstage Medical, Inc. | 1 | $25 |
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
$11,250 in reported general payments places this provider in the 75th percentile of 1,341 nephrology 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 |
|---|---|---|
| JardianceEmpagliflozin | 376 | $309,406 |
| FarxigaDapagliflozin Propanediol | 164 | $143,438 |
| OzempicSemaglutide | 114 | $110,390 |
| ProcritEpoetin Alfa | 97 | $71,256 |
| XphozahTenapanor Hcl | 24 | $67,659 |
| KerendiaFinerenone | 57 | $53,772 |
| VeltassaPatiromer Calcium Sorbitex | 37 | $51,046 |
| RayaldeeCalcifediol | 22 | $26,090 |
| JanuviaSitagliptin Phosphate | 18 | $21,920 |
| RybelsusSemaglutide | 22 | $21,653 |
| Sevelamer Carbonate | 48 | $17,202 |
| TradjentaLinagliptin | 12 | $14,028 |
| LokelmaSodium Zirconium Cyclosilicate | 18 | $13,950 |
| InvokanaCanagliflozin | 16 | $13,596 |
| DapagliflozinDapagliflozin Propanediol | 19 | $11,184 |
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 |
|---|---|---|
| Boehringer IngelheimJardiance, Tradjenta | $253 | $323,434388 claims |
| AstraZenecaFarxiga, Lokelma | $1,238 | $157,388182 claims |
| Novo NordiskOzempic, Rybelsus | $263 | $132,042136 claims |
| Johnson & JohnsonProcrit, Invokana | $44 | $84,852113 claims |
| BayerKerendia | $206 | $53,77257 claims |
| OPKO Pharmaceuticals, LLCRayaldee | $101 | $26,09022 claims |
| ANI Pharmaceuticals, Inc.Valsartan | $167 | $91521 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 75th percentile of 1,341 nephrology providers in California.
Other nephrology in Oakland
- Anjay RastogiLos Angeles$6.3M
- Aamir JamalSan Dimas$5.5M
- Mohamed El-ShahawyLos Angeles$4.4M
- Kalpesh PatelCalabasas$3.6M
- Jehad HaggiagiMission Hills$3.6M
- Malvin YanSouth Gate$3.3M
- Sohan DuaNorthridge$3.2M
- Richard LafayetteStanford$3M
- Anant DesaiGranada Hills$2.9M
- Glenn ChertowStanford$2.2M
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.