Marc Zelkowitz, MD
Nephrology · Englewood, NJNPI 1609134576
Payments from drug & device makers
What this record shows
This record is dominated by speaking fees: $11,200 of the $16,996 with a category attached, or 65.9%. Ardelyx, Inc. accounts for 71.8% of it on its own, with 22 other manufacturers making up the rest. 2025 is the largest year on record at $13,109, more than ten times the $326 reported in 2019. Among nephrology clinicians in NJ 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 361 payments — averaging $47.08 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Ardelyx, Inc.$12K
- Amgen$1K
- Vifor Pharma, Inc.$870
- AstraZeneca$596
- Bayer$451
- Travere Therapeutics, Inc.$432
- plus $1K from 17 others
Across 1 payment — averaging $1225.00 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$1K
What the payments were for
- Consulting fees$2381%
- Speaking & faculty fees$11,20066%
- Travel & lodging$2662%
- Food & beverage$5,24631%
- Education$470%
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 |
|---|---|---|
| Ardelyx, Inc. | 45 | $12,208 |
| Amgen(2 entities) | 83 | $1,175 |
| Vifor Pharma, Inc. | 57 | $870 |
| AstraZeneca | 24 | $596 |
| Bayer | 32 | $451 |
| Travere Therapeutics, Inc. | 29 | $432 |
| Akebia Therapeutics Inc | 24 | $260 |
| Novartis | 10 | $173 |
| Boehringer Ingelheim | 11 | $170 |
| Otsuka America Pharmaceutical, Inc. | 12 | $158 |
| Calliditas Therapeutics US Inc. | 7 | $108 |
| Fresenius USA Marketing, Inc. | 7 | $100 |
| Aurinia Pharma U.S., Inc. | 6 | $87 |
| Novo Nordisk | 3 | $42 |
| Otsuka Pharmaceutical Development & Commercialization, Inc. | 2 | $31 |
| ANI Pharmaceuticals, Inc. | 2 | $30 |
| Kyowa Kirin, Inc. | 1 | $18 |
| Johnson & Johnson | 1 | $18 |
| Boston Scientific | 1 | $14 |
| GSK | 1 | $14 |
| Mallinckrodt Hospital Products Inc. | 1 | $14 |
| Renalytix AI, Inc. | 1 | $14 |
| OPKO Pharmaceuticals, LLC | 1 | $12 |
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
$16,996 in reported general payments places this provider in the 95th percentile of 413 nephrology providers in New Jersey.
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 |
|---|---|---|
| FarxigaDapagliflozin Propanediol | 166 | $141,561 |
| JardianceEmpagliflozin | 53 | $60,543 |
| KerendiaFinerenone | 47 | $49,279 |
| AuryxiaFerric Citrate | 22 | $34,147 |
| LokelmaSodium Zirconium Cyclosilicate | 28 | $27,546 |
| VeltassaPatiromer Calcium Sorbitex | 24 | $22,700 |
| Sevelamer Carbonate | 34 | $3,286 |
| Midodrine Hcl | 14 | $1,606 |
| Potassium Citrate ErPotassium Citrate | 21 | $1,505 |
| Calcitriol | 112 | $1,486 |
| Losartan Potassium | 134 | $1,246 |
| Torsemide | 41 | $1,169 |
| Labetalol Hcl | 13 | $1,161 |
| Amlodipine Besylate | 82 | $644 |
| Valsartan | 17 | $500 |
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 | $596 | $169,108194 claims |
| Boehringer IngelheimJardiance | $170 | $60,54353 claims |
| BayerKerendia | $451 | $49,27947 claims |
| Akebia Therapeutics IncAuryxia | $260 | $34,14722 claims |
| ANI Pharmaceuticals, Inc.Valsartan | $30 | $50017 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 413 nephrology providers in New Jersey.
Other nephrology in Englewood
- Louis JanEnglewood$25K
- Gerald GrodsteinEnglewood$7K
- Samuel AgahiuEnglewood$6K
- Lawrence ByrdLivingston$338K
- Jeffrey FeldmanUnion$315K
- Joshua KaplanNewark$154K
- Vadim FinkielsteinPrinceton Junction$139K
- Neeraj SinghNew Brunswick$133K
- Harry DounisNeptune$75K
- Kenneth LissEatontown$75K
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.