William Frederick Ergen, M.D.
NPI 1710249529ActiveIndividual· Internal Medicine, Gastroenterology· Knoxville, TN
Internal Medicine, Gastroenterology (M.D.) in Knoxville, Tennessee, trained at University of Tennessee, Hsc, College of Medicine (class of 2012). Their prescriptions cost Medicare Part D more than their services did: $3,704,861 for 1,538 claims, against $484,478 paid for services in 2024. Abbvie Inc. was the largest of 10 companies reporting payments in 2025, $734.91 in all, mostly food and beverage.
Overview
| NPI | 1710249529 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Jun 8, 2012 |
| Last updated in NPPES | Apr 10, 2025 |
| Certified by provider | Apr 10, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 51868 | 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 | 430 |
|---|---|
| Services billed | 24,637 across 36 procedure codes |
| Paid by Medicare | $484,478 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,538 · 2,841 30-day fills |
|---|---|
| Patients | 524 |
| Total drug cost | $3,704,861 |
| Generic share | 73% of claims |
Education and affiliations
| Medical school | University of Tennessee, Hsc, College of Medicine |
|---|---|
| Graduation year | 2012 |
| Medicare specialty | Gastroenterology |
Medical group
- Gastrointestinal Associates PCKnoxville, TN · 33 clinicians
Hospital affiliations
- Fort Sanders Regional Medical CenterKnoxville, TN
- Leconte Medical CenterSevierville, TN
- Parkwest Medical CenterKnoxville, TN
- Physicians Regional Medical CenterPowell, TN
- University Health System, IncKnoxville, TN
Industry payments (Open Payments)
- 2025$734.91 · 46 payments from 10 companies
- 2024$938.11 · 57 payments from 9 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $365.37 | 29 |
| Celltrion USA Inc. | $81.95 | 4 |
| Ardelyx, Inc. | $80.14 | 3 |
| Ferring Pharmaceuticals Inc. | $67.97 | 3 |
| Pfizer Inc. | $32.06 | 2 |
What the 2025 payments were for
- Food and Beverage$734.91 · 46 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