Stuart Sprague, DO
Nephrology · Evanston, ILNPI 1114947124
Payments from drug & device makers
What this record shows
The money is spread across several categories — speaking fees (59.2%), consulting fees and travel and lodging — rather than concentrated in one kind of arrangement. 30 manufacturers reported payments, led by Ardelyx, Inc. at 32.3% of the total. Reporting peaked in 2022 at $118,590 and has fallen 79.2% since, to $24,686 in 2025. Among nephrology clinicians in IL 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 464 payments — averaging $727.21 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Ardelyx, Inc.$109K
- Amgen$64K
- Bayer$49K
- OPKO Pharmaceuticals, LLC$37K
- Fresenius USA Marketing, Inc.$27K
- Kyowa Kirin, Inc.$20K
- plus $33K from 24 others
Across 77 payments — averaging $4001.76 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.
- Ardelyx, Inc.$78K
- Takeda Pharmaceuticals U.S.A., Inc.$61K
- AstraZeneca$51K
- Amgen$34K
- OPKO Pharmaceuticals, LLC$27K
- Beigene USA, Inc.$18K
- plus $40K from 5 others
What the payments were for
- Consulting fees$117,01335%
- Speaking & faculty fees$199,90059%
- Travel & lodging$10,0183%
- Food & beverage$9,9113%
- Education$5850%
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. | 62 | $108,914 |
| Amgen(2 entities) | 97 | $63,515 |
| Bayer | 47 | $48,786 |
| OPKO Pharmaceuticals, LLC | 35 | $36,729 |
| Fresenius USA Marketing, Inc. | 34 | $26,574 |
| Kyowa Kirin, Inc. | 29 | $20,188 |
| AstraZeneca(2 entities) | 51 | $13,931 |
| Shire North American Group Inc | 6 | $6,146 |
| Ultragenyx Pharmaceutical Inc. | 7 | $4,643 |
| Ascendis Pharma Endocrinology Inc | 4 | $3,641 |
| Vifor Fresenius Medical Care Renal Pharma Ltd. | 1 | $1,400 |
| Travere Therapeutics, Inc. | 28 | $789 |
| Novartis | 7 | $349 |
| GSK | 5 | $304 |
| Mallinckrodt Hospital Products Inc. | 6 | $229 |
| Calliditas Therapeutics US Inc. | 9 | $185 |
| Akebia Therapeutics Inc | 3 | $171 |
| Otsuka America Pharmaceutical, Inc. | 8 | $170 |
| Novo Nordisk | 2 | $141 |
| Takeda Pharmaceuticals U.S.A., Inc. | 1 | $125 |
| ANI Pharmaceuticals, Inc. | 5 | $124 |
| Vifor Pharma, Inc. | 4 | $123 |
| Aurinia Pharma U.S., Inc. | 5 | $99 |
| Xeris Pharmaceuticals, Inc. | 2 | $39 |
| Alvogen Inc | 1 | $24 |
| Recor Medical Inc | 1 | $22 |
| Alnylam Pharmaceuticals Inc. | 1 | $20 |
| Medtronic | 1 | $17 |
| Daiichi Sankyo Inc. | 1 | $17 |
| Arbor Pharmaceuticals, Inc. | 1 | $13 |
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.
- Kerendia$48,037
- XPHOZAH 30 MG$45,571
- Rayaldee$36,445
- KRYSTEXXA$35,836
- Parsabiv$25,674
- Velphoro$24,704
- CRYSVITA$18,937
- LOKELMA$12,922
- NATPARA (PARATHYROID HORMONE)$6,227
- Cryvista$1,875
- Yorvipath$1,248
- (815) Thiola$252
- BENLYSTA$246
- Critline - Monitors$125
- AURYXIA$123
- Vafseo$123
- Fabhalta$120
- Rivfloza$120
How this compares
$337,427 in reported general payments places this provider in the 95th percentile of 524 nephrology providers in Illinois.
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 |
|---|---|---|
| ForteoTeriparatide | 22 | $96,693 |
| XphozahTenapanor Hcl | 22 | $83,399 |
| Teriparatide | 18 | $48,161 |
| TymlosAbaloparatide | 18 | $46,282 |
| RayaldeeCalcifediol | 23 | $40,212 |
| KerendiaFinerenone | 25 | $38,841 |
| FarxigaDapagliflozin Propanediol | 40 | $31,857 |
| LokelmaSodium Zirconium Cyclosilicate | 16 | $19,667 |
| Potassium Citrate ErPotassium Citrate | 141 | $18,277 |
| Indapamide | 314 | $3,892 |
| Cinacalcet Hcl | 14 | $3,494 |
| Sevelamer Carbonate | 21 | $2,617 |
| Tacrolimus | 16 | $1,862 |
| Chlorthalidone | 140 | $1,727 |
| Potassium Chloride | 53 | $1,485 |
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 | $13,931 | $51,52456 claims |
| Alvogen IncTeriparatide | $24 | $48,16118 claims |
| OPKO Pharmaceuticals, LLCRayaldee | $36,729 | $40,21223 claims |
| BayerKerendia | $48,786 | $38,84125 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 524 nephrology providers in Illinois.
Other nephrology in Evanston
- Louisa HoEvanston$8K
- Myles WolfChicago$2.1M
- Mohammed AhmedBolingbrook$1.1M
- Anis RaufHinsdale$453K
- Juan LermaEvergreen Park$351K
- Suneel UdaniHinsdale$336K
- Susan QuagginChicago$262K
- Nicole StankusChicago$235K
- Omaima DeganiGurnee$184K
- Merry DownerSpringfield$156K
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.