Dr. William F. Ergen, M.D.
Gastroenterology (Gastroenterology Physician)
- Medicare participating
At a glance
- Medical school
- University of Tennessee, Hsc, College of Medicine (2012)
- Years since graduation
- 14
- In the NPI registry since
- 2012
- Medicare patients seen, 2024
- 430
The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. What an NPI is
Education and training
- 2012Medical school: University of Tennessee, Hsc, College of Medicine
- 2012Registered with an NPI (national billing number; not a license date)
Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).
Specialties and state licenses
-
Gastroenterology Physician primary
TN license 51868
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- University Health System, Inc Knoxville, TN
- Parkwest Medical Center Knoxville, TN
- Fort Sanders Regional Medical Center Knoxville, TN
- Physicians Regional Medical Center Powell, TN
- Leconte Medical Center Sevierville, TN
Medical groups
- Gastrointestinal Associates PC (33 clinicians)
Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.
Medicare patients and services
- Medicare patients, 2024
- 430
- Services billed
- 24,637
- Patients’ average age
- 72
| Service | Times | Patients |
|---|---|---|
| Injection, vedolizumab, 1 mg | 15,900 | 14 |
| Established patient office or other outpatient visit, 20-29 minutes | 220 | 169 |
| Removal of polyps or growths of large bowel using an endoscope with mechanical snare | 154 | 154 |
| Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | 117 | 114 |
| New patient office or other outpatient visit, 30-44 minutes | 78 | 78 |
| Administration of chemotherapy into vein, 1 hour or less | 73 | 20 |
| Biopsy of large bowel using a flexible endoscope | 60 | 60 |
| Dilation of esophagus | 37 | 36 |
| Colorectal cancer screening; colonoscopy on individual at high risk | 27 | 27 |
| Chronic care management services, first 20 minutes of clinical staff time directed by health care professional, per calendar month | 19 | 19 |
Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.
Medicare prescriptions
| Drug | Prescriptions |
|---|---|
| Omeprazole Other prescribers in Knoxville, TN | 232 |
| Sod Sulf-Potass Sulf-Mag Sulf (sodium, potassium,mag sulfates) Other prescribers in Knoxville, TN | 168 |
| Famotidine Other prescribers in Knoxville, TN | 130 |
| Pantoprazole Sodium Other prescribers in Knoxville, TN | 128 |
| Stelara (ustekinumab) | 100 |
| Linzess (linaclotide) Other prescribers in Knoxville, TN | 80 |
| Gavilyte-G (peg3350/sod sulf,bicarb,cl/kcl) Other prescribers in Knoxville, TN | 43 |
| Dexlansoprazole Dr (dexlansoprazole) Other prescribers in Knoxville, TN | 41 |
| Sucralfate Other prescribers in Knoxville, TN | 40 |
| Azathioprine Other prescribers in Knoxville, TN | 36 |
Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.
Payments from drug and device companies
In 2025, 10 companies reported 46 payments worth $735 in total to this clinician.
| AbbVie Inc. | $365 |
|---|---|
| Celltrion USA Inc. | $81.95 |
| Ardelyx, Inc. | $80.14 |
| Ferring Pharmaceuticals Inc. | $67.97 |
| Pfizer Inc. | $32.06 |
| Janssen Biotech, Inc. | $30.04 |
| Madrigal Pharmaceuticals | $26.89 |
| Lilly USA, LLC | $17.87 |
| Food and Beverage | $735 |
|---|
From CMS Open Payments. A payment is not evidence of wrongdoing; many are for consulting, teaching or meals. Clinicians can review and dispute their records with CMS.
Industry-funded research
Named as a principal investigator on 1 industry-funded study in 2025, from 1 company. The companies reported $17,850 in research payments for these studies, mostly to the institutions running them.
- A Study to Assess the Change in Disease Activity in Adult Participants With Moderate to Severe Ulcerative Colitis Treated With Risankizumab Compared to Vedolizumab
AbbVie Inc. · Active, not recruiting · NCT06880744
From CMS Open Payments research payments, where companies name up to five principal investigators per payment. Research payments usually go to hospitals, universities and research sites, not to the investigator personally. A payment is not evidence of wrongdoing.