John Michael Haydek, MD
NPI 1275508095ActiveIndividual· Internal Medicine, Gastroenterology· Knoxville, TN
Internal Medicine, Gastroenterology (MD) in Knoxville, Tennessee, trained at Loyola University of Chicago, Stritch School of Medicine (class of 1988). In 2024 Medicare paid $194,026 for 708 patients, and Part D covered 1,284 of their prescriptions, 82% of them generic. Abbvie Inc. was the largest of 3 companies reporting payments in 2025, $239.13 in all, mostly food and beverage.
Overview
| NPI | 1275508095 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Feb 23, 2006 |
| Last updated in NPPES | May 4, 2017 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | MD27845 | TN |
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 (TN) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 708 |
|---|---|
| Services billed | 5,410 across 38 procedure codes |
| Paid by Medicare | $194,026 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,284 · 2,556 30-day fills |
|---|---|
| Patients | 531 |
| Total drug cost | $201,666 |
| Generic share | 82% of claims |
Education and affiliations
| Medical school | Loyola University of Chicago, Stritch School of Medicine |
|---|---|
| Graduation year | 1988 |
| Medicare specialty | Gastroenterology |
Medical group
- Gastrointestinal Associates PCKnoxville, TN · 33 clinicians
Hospital affiliations
- Fort Sanders Regional Medical CenterKnoxville, TN
- Parkwest Medical CenterKnoxville, TN
- Physicians Regional Medical CenterPowell, TN
- University Health System, IncKnoxville, TN
Industry payments (Open Payments)
- 2025$239.13 · 19 payments from 3 companies
- 2024$453.09 · 26 payments from 6 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $172.99 | 15 |
| Janssen Biotech, Inc. | $46.92 | 3 |
| Phathom Pharmaceuticals, Inc. | $19.22 | 1 |
What the 2025 payments were for
- Food and Beverage$239.13 · 19 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 56 gastroenterologists in Knoxville · All gastroenterologists in Tennessee