Gwendolen Chang, MD
Internal Medicine · San Leandro, CANPI 1386807402
Payments from drug & device makers
What this record shows
Almost everything reported here is food and beverage — 96.7% of the total across 223 separate payments, which is the pattern of a clinician who attends manufacturer presentations rather than one with a consulting arrangement. It is spread thinly across 22 manufacturers, the largest accounting for just 17.4% — the pattern of someone who eats at a lot of different presentations. 2025 is the largest year on record at $1,616, more than ten times the $101 reported in 2019. Among internal medicine 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 223 payments — averaging $23.09 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Fresenius USA Marketing, Inc.$896
- AstraZeneca$831
- Otsuka America Pharmaceutical, Inc.$557
- Novartis$539
- Amgen$460
- Mallinckrodt Hospital Products Inc.$265
- plus $2K from 16 others
What the payments were for
- Food & beverage$4,98197%
- Education$1693%
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 |
|---|---|---|
| Fresenius USA Marketing, Inc. | 46 | $896 |
| AstraZeneca | 37 | $831 |
| Otsuka America Pharmaceutical, Inc. | 24 | $557 |
| Novartis | 20 | $539 |
| Amgen(2 entities) | 20 | $460 |
| Mallinckrodt Hospital Products Inc. | 11 | $265 |
| Calliditas Therapeutics US Inc. | 10 | $247 |
| Bayer | 8 | $228 |
| OPKO Pharmaceuticals, LLC | 12 | $197 |
| ANI Pharmaceuticals, Inc. | 7 | $162 |
| Ardelyx, Inc. | 5 | $144 |
| Vifor Pharma, Inc. | 5 | $136 |
| Oyster Point Pharma, Inc. | 1 | $119 |
| Travere Therapeutics, Inc. | 5 | $96 |
| Aurinia Pharma U.S., Inc. | 3 | $77 |
| Novo Nordisk | 3 | $48 |
| Apellis Pharmaceuticals, Inc. | 1 | $31 |
| GSK | 1 | $25 |
| Lilly USA, LLC | 1 | $24 |
| Mallinckrodt Enterprises LLC | 1 | $24 |
| La Jolla Pharmaceutical Company | 1 | $24 |
| Akebia Therapeutics Inc | 1 | $20 |
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.
- TYRVAYA$119
How this compares
$5,149 in reported general payments places this provider in the 90th percentile of 13,581 internal medicine 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 |
|---|---|---|
| JynarqueTolvaptan | 11 | $186,839 |
| FarxigaDapagliflozin Propanediol | 176 | $142,152 |
| RayaldeeCalcifediol | 57 | $68,619 |
| VeltassaPatiromer Calcium Sorbitex | 52 | $60,625 |
| XphozahTenapanor Hcl | 17 | $53,703 |
| LokelmaSodium Zirconium Cyclosilicate | 55 | $45,895 |
| JardianceEmpagliflozin | 43 | $45,564 |
| Sevelamer Carbonate | 57 | $22,834 |
| AranespDarbepoetin Alfa In Polysorbat | 19 | $14,103 |
| Lanthanum Carbonate | 18 | $14,021 |
| DapagliflozinDapagliflozin Propanediol | 14 | $9,995 |
| JanuviaSitagliptin Phosphate | 13 | $7,146 |
| ClinolipidFat Emulsion/Olive/Soy/Phospho | 14 | $3,645 |
| Febuxostat | 46 | $3,615 |
| ProcritEpoetin Alfa | 14 | $3,199 |
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 |
|---|---|---|
| AstraZenecaFarxiga, Lokelma | $831 | $188,047231 claims |
| Otsuka America Pharmaceutical, Inc.Jynarque | $557 | $186,83911 claims |
| OPKO Pharmaceuticals, LLCRayaldee | $197 | $68,61957 claims |
| AmgenAranesp | $460 | $14,10319 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 13,581 internal medicine providers in California.
Other internal medicine in San Leandro
- Andrew ChengSouth San Francisco$55.1M
- Tung NgoNewport Beach$4.9M
- Christian EversullStanford$2.9M
- Christian SandrockSacramento$2.1M
- Hatim HusainSan Diego$2M
- Teck LingPalo Alto$1.1M
- Hyong Kimla Jolla$1M
- Rohit Loombala Jolla$965K
- Fred CohenSan Francisco$929K
- Steven EdelmanSan Diego$863K
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.