Michael J. Zerega, MD
NPI 1073505178ActiveIndividual· Internal Medicine, Gastroenterology· Lake St Louis, MO
Internal Medicine, Gastroenterology (MD) in Lake St Louis, Missouri, trained at Washington University School of Medicine (class of 1997). Their prescriptions cost Medicare Part D more than their services did: $740,036 for 1,287 claims, against $65,089 paid for services in 2024. Janssen Biotech, Inc. was the largest of 4 companies reporting payments in 2025, $289.40 in all, mostly food and beverage.
Overview
| NPI | 1073505178 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Aug 16, 2005 |
| Last updated in NPPES | Apr 2, 2015 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 2000154596 | MO |
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 (MO) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 373 |
|---|---|
| Services billed | 552 across 33 procedure codes |
| Paid by Medicare | $65,089 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,287 · 2,154 30-day fills |
|---|---|
| Patients | 665 |
| Total drug cost | $740,036 |
| Generic share | 87% of claims |
Education and affiliations
| Medical school | Washington University School of Medicine |
|---|---|
| Graduation year | 1997 |
| Medicare specialty | Gastroenterology |
Medical group
- Mercy Clinic Gastroenterology LLCWashington, MO · 67 clinicians
Hospital affiliations
- Mercy Hospital SouthSaint Louis, MO
- Mercy Hospital St LouisSaint Louis, MO
- Mercy Hospital WashingtonWashington, MO
- Missouri Baptist Medical CenterSaint Louis, MO
Industry payments (Open Payments)
- 2025$289.40 · 5 payments from 4 companies
- 2024$48.39 · 2 payments from 2 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Janssen Biotech, Inc. | $178.80 | 2 |
| Micro-Tech Endoscopy USA, Inc. | $69.10 | 1 |
| Genzyme Corporation | $21.20 | 1 |
| Pfizer Inc. | $20.30 | 1 |
What the 2025 payments were for
- Food and Beverage$205.40 · 4 payments
- Education$84.00 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All Internal Medicine, Gastroenterology providers in Missouri →