Joan Chen, MD
Gastroenterology · Ann Arbor, MINPI 1932371713
Payments from drug & device makers
What this record shows
The money is spread across several categories — speaking fees (51.7%), consulting fees and travel and lodging — rather than concentrated in one kind of arrangement. Phathom Pharmaceuticals, Inc. accounts for 74.4% of it on its own, with 4 other manufacturers making up the rest. Reporting peaked in 2024 at $11,482 and has fallen 98.8% since, to $138 in 2025. Among gastroenterology clinicians in MI 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 32 payments — averaging $770.96 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Phathom Pharmaceuticals, Inc.$18K
- Merck$5K
- Sanofi$870
- Regeneron Healthcare Solutions, Inc.$132
- Dova Pharmaceuticals$87
Across 129 payments — averaging $2983.93 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.
- Regeneron$369K
- Adare Pharmaceuticals, Inc.$16K
What the payments were for
- Consulting fees$9,36238%
- Speaking & faculty fees$12,75052%
- Travel & lodging$1,5046%
- Food & beverage$1,0554%
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 |
|---|---|---|
| Phathom Pharmaceuticals, Inc. | 21 | $18,357 |
| Merck | 1 | $5,225 |
| Sanofi | 6 | $870 |
| Regeneron Healthcare Solutions, Inc. | 3 | $132 |
| Dova Pharmaceuticals | 1 | $87 |
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.
- VOQUEZNA$16,438
- VOQUEZNA TRIPLE PAK$7,000
- VOQUEZNA DUAL PAK$7,000
- GARDASIL$5,225
- DUPIXENT$637
How this compares
$24,671 in reported general payments places this provider in the 90th percentile of 497 gastroenterology providers in Michigan.
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 |
|---|---|---|
| Esomeprazole Magnesium | 17 | $4,391 |
| Omeprazole | 85 | $2,022 |
| Peg 3350-ElectrolyteSodium Chloride/Nahco3/Kcl/Peg | 31 | $970 |
| Pantoprazole Sodium | 17 | $356 |
| Famotidine | 11 | $213 |
Paid to pharmacies, not to this prescriber.
Other gastroenterology in Ann Arbor
- Philip SchoenfeldAnn Arbor$539K
- Michelle Muza-MoonsAnn Arbor$481K
- Allison SchulmanAnn Arbor$124K
- Eric ShahAnn Arbor$120K
- Peter HigginsAnn Arbor$111K
- Neehar ParikhAnn Arbor$101K
- William CheyAnn Arbor$90K
- Ryan StidhamAnn Arbor$83K
- Elliot TapperAnn Arbor$69K
- Michael RiceAnn Arbor$48K
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.