Claus J. Fimmel, MD
NPI 1568417780ActiveIndividual· Internal Medicine, Gastroenterology· Northbrook, IL
Internal Medicine, Gastroenterology (MD) with St Vincent Hospital-Hospital Sisters-Third Order of St Francis, practicing in Northbrook, Illinois. Their prescriptions cost Medicare Part D more than their services did: $35,975 for 260 claims, against $21,378 paid for services in 2024. Madrigal Pharmaceuticals was the largest of 9 companies reporting payments in 2025, $883.12 in all, mostly food and beverage. Lists Northshore University Healthsystem - Evanston Hospital and 2 other hospitals as hospital affiliations.
Overview
| NPI | 1568417780 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | May 24, 2006 |
| Last updated in NPPES | Nov 19, 2025 |
| Certified by provider | Nov 19, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 036115700 | IL |
| Internal Medicine, Gastroenterology | 207RG0100X | 13614-320 | WI |
| Internal Medicine | 207R00000X | 036115700 | IL |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Gastroenterology (IL); Practitioner - Gastroenterology (WI) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 149 |
|---|---|
| Services billed | 236 across 31 procedure codes |
| Paid by Medicare | $21,378 |
Part D prescriptions in 2024
| Prescriptions (claims) | 260 · 490 30-day fills |
|---|---|
| Patients | 119 |
| Total drug cost | $35,975 |
| Generic share | 85% of claims |
Education and affiliations
| Graduation year | 1981 |
|---|---|
| Medicare specialty | Gastroenterology |
Medical group
- St Vincent Hospital-Hospital Sisters-Third Order of St FrancisGreen Bay, WI · 603 clinicians
Hospital affiliations
- Northshore University Healthsystem - Evanston HospitalEvanston, IL
- St Marys Hospital Medical CtrGreen Bay, WI
- St Vincent HospitalGreen Bay, WI
Industry payments (Open Payments)
- 2025$883.12 · 24 payments from 9 companies
- 2024$176.53 · 8 payments from 6 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Madrigal Pharmaceuticals | $417.03 | 4 |
| Gilead Sciences, Inc. | $211.98 | 9 |
| Intercept Pharmaceuticals, Inc. | $74.52 | 3 |
| Ardelyx, Inc. | $48.54 | 2 |
| Mirum Pharmaceuticals, Inc. | $44.69 | 2 |
What the 2025 payments were for
- Food and Beverage$883.12 · 24 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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