Mark L. Stillwell, M.D.
NPI 1568459451ActiveIndividual· Internal Medicine, Infectious Disease· Fort Smith, AR
Internal Medicine, Infectious Disease (M.D.) in Fort Smith, Arkansas, trained at University of Maryland School of Medicine (class of 1982). 30 Medicare patients in 2024, $16,367 paid; nearly all of their 74 Part D prescriptions were generic (91%). Abbvie Inc. was the largest of 7 companies reporting payments in 2025, $780.33 in all, mostly food and beverage.
Overview
| NPI | 1568459451 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | Yes |
| NPI issued | Oct 5, 2005 |
| Last updated in NPPES | Oct 18, 2024 |
| Certified by provider | Oct 18, 2024 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Infectious Disease Primary | 207RI0200X | N7411 | AR |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Infectious Disease (AR) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 30 |
|---|---|
| Services billed | 214 across 15 procedure codes |
| Paid by Medicare | $16,367 |
Part D prescriptions in 2024
| Prescriptions (claims) | 74 · 77 30-day fills |
|---|---|
| Patients | 16 |
| Total drug cost | $6,395 |
| Generic share | 91% of claims |
Education and affiliations
| Medical school | University of Maryland School of Medicine |
|---|---|
| Graduation year | 1982 |
| Medicare specialty | Infectious Disease |
| Secondary specialties | Internal Medicine |
Medical group
- Mercy Clinic Fort Smith CommunitiesFort Smith, AR · 372 clinicians
Hospital affiliations
- Mercy Hospital Fort SmithFort Smith, AR
- Sequoyah County-City of Sallisaw Hospital AuthoritSallisaw, OK
Industry payments (Open Payments)
- 2025$780.33 · 24 payments from 7 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $238.30 | 9 |
| Viiv Healthcare Company | $234.97 | 6 |
| Gilead Sciences, Inc. | $134.68 | 1 |
| Paratek Pharmaceuticals, Inc. | $79.39 | 3 |
| Merck Sharp & Dohme LLC | $42.32 | 2 |
What the 2025 payments were for
- Food and Beverage$780.33 · 24 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All Internal Medicine, Infectious Disease providers in Arkansas →