Joshua Knowles, MD
Cardiovascular Disease · Stanford, CANPI 1538201520
Payments from drug & device makers
What this record shows
This record is dominated by speaking fees: $519 of the $671 with a category attached, or 77.3%. Bayer accounts for 77.3% of it on its own, with 2 other manufacturers making up the rest. Reporting peaked in 2020 at $519 and has fallen 94.6% since, to $28 in 2023. That places this record below the midpoint for cardiovascular disease clinicians in CA, where the typical reported total is $2,142.
Across 3 payments — averaging $223.78 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Bayer$519
- E.r. Squibb & Sons, L.L.C.$125
- Novartis$28
Across 11 payments — averaging $19,491 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.
- Novartis$214K
What the payments were for
- Speaking & faculty fees$51977%
- Food & beverage$15223%
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 |
|---|---|---|
| Bayer | 1 | $519 |
| E.r. Squibb & Sons, L.L.C. | 1 | $125 |
| Novartis | 1 | $28 |
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.
- Non-Covered$519
How this compares
$671 in reported general payments places this provider in the 30th percentile of 2,184 cardiovascular disease 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 |
|---|---|---|
| CamzyosMavacamten | 13 | $105,856 |
| Repatha SureclickEvolocumab | 128 | $104,712 |
| Praluent PenAlirocumab | 72 | $34,884 |
| EliquisApixaban | 17 | $29,377 |
| XareltoRivaroxaban | 12 | $18,102 |
| WegovySemaglutide | 13 | $16,724 |
| Ezetimibe | 72 | $2,701 |
| Rosuvastatin Calcium | 78 | $1,916 |
| Metoprolol Succinate | 62 | $800 |
| Atorvastatin Calcium | 93 | $771 |
| Colesevelam Hcl | 12 | $327 |
| Carvedilol | 44 | $322 |
| Lisinopril | 13 | $241 |
| Losartan Potassium | 23 | $222 |
| Amlodipine Besylate | 34 | $164 |
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 |
|---|---|---|
| E.r. Squibb & Sons, L.L.C.Camzyos | $125 | $105,85613 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 30th percentile of 2,184 cardiovascular disease providers in California.
Other cardiovascular disease in Stanford
- Wilber SuStanford$1.1M
- Euan AshleyStanford$508K
- Kenneth MahaffeyStanford$447K
- Ted LoveHillsborough$102.8M
- Paul KurthSanta Barbara$6.1M
- Jason RogersSacramento$4.4M
- Matthew BudoffTorrance$3.6M
- Eric Topolla Jolla$2.2M
- Cathleen Bairey-MerzLos Angeles$1.2M
- Gagan SinghSacramento$1.2M
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.