John E. Fassler, MD
NPI 1891798757ActiveIndividual· Internal Medicine, Nephrology· Rock Hill, SC
Internal Medicine, Nephrology (MD) in Rock Hill, South Carolina, trained at Ohio State University College of Medicine (class of 1991). 627 Medicare patients in 2024, $150,008 paid; nearly all of their 532 Part D prescriptions were generic (91%). Sanofi-Aventis U.S. LLC was the largest of 3 companies reporting payments in 2025, $211.70 in all, mostly food and beverage.
Overview
| NPI | 1891798757 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | May 24, 2005 |
| Last updated in NPPES | Feb 5, 2026 |
| Certified by provider | Feb 5, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Nephrology Primary | 207RN0300X | 19767 | SC |
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 - Nephrology (NC); Practitioner - Nephrology (SC); Practitioner - Nephrology (WI) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 627 |
|---|---|
| Services billed | 2,513 across 26 procedure codes |
| Paid by Medicare | $150,008 |
Part D prescriptions in 2024
| Prescriptions (claims) | 532 · 1,105 30-day fills |
|---|---|
| Patients | 134 |
| Total drug cost | $42,334 |
| Generic share | 91% of claims |
Education and affiliations
| Medical school | Ohio State University College of Medicine |
|---|---|
| Graduation year | 1991 |
| Medicare specialty | Nephrology |
| Secondary specialties | Internal Medicine |
Medical group
- Nephrology Associates PARock Hill, SC · 11 clinicians
Hospital affiliation
- Piedmont Medical CenterRock Hill, SC
Other facilities
- Davita Fort Mill DialysisDialysis facility · Fort Mill, SC
- Fmc of Fort MillDialysis facility · Fort Mill, SC
- Encompass Health Rehabilitation Hospital of Rock HInpatient rehabilitation facility · Rock Hill, SC
Industry payments (Open Payments)
- 2025$211.70 · 4 payments from 3 companies
- 2024$65.55 · 3 payments from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Sanofi-Aventis U.S. LLC | $110.00 | 1 |
| Vantive US Healthcare LLC | $50.94 | 1 |
| Calliditas Therapeutics US Inc. | $50.76 | 2 |
What the 2025 payments were for
- Food and Beverage$211.70 · 4 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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