Charles McMahon, MD
Gastroenterology · Kansas City, MONPI 1861768053
Payments from drug & device makers
Across 133 payments — averaging $19.18 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- AbbVie$1K
- Bristol Myers Squibb$255
- Ardelyx, Inc.$241
- Johnson & Johnson$185
- Celltrion USA Inc.$119
- Pfizer$88
- plus $578 from 14 others
What the payments were for
- Food & beverage$2,50098%
- Education$502%
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 |
|---|---|---|
| AbbVie | 58 | $1,085 |
| Bristol Myers Squibb | 17 | $255 |
| Ardelyx, Inc. | 10 | $241 |
| Johnson & Johnson | 7 | $185 |
| Celltrion USA Inc. | 7 | $119 |
| Pfizer | 4 | $88 |
| Takeda Pharmaceuticals U.S.A., Inc. | 4 | $80 |
| Merck | 4 | $71 |
| Ferring Pharmaceuticals Inc. | 3 | $65 |
| Sanofi | 2 | $59 |
| Daiichi Sankyo Inc. | 2 | $52 |
| Aimmune Therapeutics, Inc. | 2 | $44 |
| Organon | 2 | $41 |
| Salix Pharmaceuticals, A Division Of Bausch Health US, LLC | 2 | $38 |
| Phathom Pharmaceuticals, Inc. | 2 | $36 |
| Micro-tech Endoscopy USA, Inc. | 3 | $25 |
| Novo Nordisk | 1 | $22 |
| Ironwood Pharmaceuticals, Inc | 1 | $21 |
| Medtronic | 1 | $15 |
| Endogastric Solutions, Inc | 1 | $9 |
How this compares
$2,550 in reported general payments places this provider in the 55th percentile of 374 gastroenterology providers in Missouri.
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 |
|---|---|---|
| StelaraUstekinumab | 14 | $382,906 |
| CreonLipase/Protease/Amylase | 12 | $37,419 |
| Sod Sulf-Potass Sulf-Mag SulfSodium, Potassium,mag Sulfates | 396 | $26,494 |
| Omeprazole | 149 | $1,954 |
| Budesonide DrBudesonide | 16 | $1,819 |
| SutabSod Sulf/Pot Chloride/Mag Sulf | 11 | $1,768 |
| Pantoprazole Sodium | 81 | $1,518 |
| Diphenoxylate-AtropineDiphenoxylate Hcl/Atropine | 15 | $1,049 |
| Dexlansoprazole DrDexlansoprazole | 11 | $822 |
| Dicyclomine Hcl | 20 | $382 |
| Famotidine | 25 | $167 |
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 |
|---|---|---|
| Johnson & JohnsonStelara | $185 | $382,90614 claims |
| AbbVieCreon | $1,085 | $37,41912 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 55th percentile of 374 gastroenterology providers in Missouri.
Other gastroenterology in Kansas City
- Bradley FreilichKansas City$4.5M
- Amit RastogiKansas City$453K
- Hillary BownikKansas City$414K
- Prashant PandyaKansas City$286K
- Laith Al MomaniKansas City$276K
- Ahmed SaeedKansas City$246K
- Michael ConnorKansas City$167K
- Tahar MahmoudiKansas City$114K
- Rajiv ChhabraKansas City$100K
- Paresh PatelKansas City$55K
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.