Joan Weichun Chen, MD
NPI 1932371713ActiveIndividual· Internal Medicine, Gastroenterology· Ann Arbor, MI
Internal Medicine, Gastroenterology (MD) in Ann Arbor, Michigan, trained at Vanderbilt University School of Medicine (class of 2005). In 2024 Medicare paid $29,329 for 211 patients, and Part D covered 216 of their prescriptions, 89% of them generic. Genzyme Corporation was the largest of 2 companies reporting payments in 2025, $137.66 in all, mostly food and beverage.
Overview
| NPI | 1932371713 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Apr 1, 2008 |
| Last updated in NPPES | Sep 3, 2013 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 4301103392 | MI |
| Internal Medicine | 207R00000X | 036119706 | IL |
| Internal Medicine | 207R00000X | 4301103392 | MI |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Gastroenterology (MI) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 211 |
|---|---|
| Services billed | 362 across 39 procedure codes |
| Paid by Medicare | $29,329 |
Part D prescriptions in 2024
| Prescriptions (claims) | 216 · 513 30-day fills |
|---|---|
| Patients | 83 |
| Total drug cost | $27,573 |
| Generic share | 89% of claims |
Education and affiliations
| Medical school | Vanderbilt University School of Medicine |
|---|---|
| Graduation year | 2005 |
| Medicare specialty | Gastroenterology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Regents of the University of MichiganAnn Arbor, MI · 3,346 clinicians
Hospital affiliation
- University of Michigan Health SystemAnn Arbor, MI
Industry payments (Open Payments)
- 2025$137.66 · 3 payments from 2 companies
- 2024$11,482 · 16 payments from 3 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Genzyme Corporation | $110.04 | 2 |
| Phathom Pharmaceuticals, Inc. | $27.62 | 1 |
What the 2025 payments were for
- Food and Beverage$137.66 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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