John A.H. Clark, M.D.
NPI 1578631784ActiveIndividual· Internal Medicine, Nephrology· Huntsville, AL
Internal Medicine, Nephrology (M.D.) in Huntsville, Alabama, trained at University of Alabama School of Medicine (class of 2002). In 2024 Medicare paid $267,604 for 520 patients, and Part D covered 1,373 of their prescriptions, 85% of them generic. Novartis Pharmaceuticals Corporation was the largest of 13 companies reporting payments in 2025, $1,370 in all, mostly food and beverage.
Overview
| NPI | 1578631784 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | Yes |
| NPI issued | Dec 4, 2006 |
| Last updated in NPPES | Apr 21, 2026 |
| Certified by provider | Apr 21, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Nephrology Primary | 207RN0300X | MD0000040647 | TN |
| Internal Medicine | 207R00000X | MD0000040647 | 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 - Nephrology (AL); Practitioner - Nephrology (TN) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 520 |
|---|---|
| Services billed | 2,263 across 45 procedure codes |
| Paid by Medicare | $267,604 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,373 · 2,776 30-day fills |
|---|---|
| Patients | 226 |
| Total drug cost | $302,995 |
| Generic share | 85% of claims |
Education and affiliations
| Medical school | University of Alabama School of Medicine |
|---|---|
| Graduation year | 2002 |
| Medicare specialty | Nephrology |
Medical groups
- Nephrology Consultants LLCHunstville, AL · 17 clinicians
- North Alabama Vascular and Dialysis Access Care LLCHuntsville, AL · 4 clinicians
Hospital affiliations
- Athens Limestone HospitalAthens, AL
- Helen Keller HospitalSheffield, AL
- Highlands Medical CenterScottsboro, AL
- Huntsville HospitalHuntsville, AL
- Marshall Medical CentersBoaz, AL
Other facilities
- Fkc FlorenceDialysis facility · Florence, AL
- Fmc Elk River DialysisDialysis facility · Fayetteville, TN
- Fmc Huntsville HomeDialysis facility · Huntsville, AL
- Fmc ScottsboroDialysis facility · Scottsboro, AL
- Fmc TranquilityDialysis facility · Meridianville, AL
Industry payments (Open Payments)
- 2025$1,370 · 63 payments from 13 companies
- 2024$941.69 · 43 payments from 17 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novartis Pharmaceuticals Corporation | $400.01 | 15 |
| Travere Therapeutics, Inc. | $144.42 | 6 |
| Vifor Pharma, Inc. | $123.89 | 5 |
| Otsuka America Pharmaceutical, Inc. | $121.29 | 6 |
| Boehringer Ingelheim Pharmaceuticals, Inc. | $92.34 | 5 |
What the 2025 payments were for
- Food and Beverage$1,370 · 63 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 25 nephrologists in Huntsville · All nephrologists in Alabama