Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Mark L Stillwell, MD

Individual provider Infectious Disease Physician · NPI 1568459451

Mark L Stillwell, MD is registered under Infectious Disease in Fort Smith, Arkansas. Graduated from University of Maryland School of Medicine in 1982, 44 years ago. Practices with Mercy Clinic Fort Smith Communities, a 350-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in Arkansas.

Years since qualifying
44
Trained at
University of Maryland School of Medicine
Licensed in
AR
In the registry since
2005
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

6801 Rogers Ave Fl 5
Fort Smith, AR 72903-4067
Phone: (479) 274-4100
Fax: (479) 274-4199
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 2900 Medical Center Parkway, Bentonville, AR 72712 — (479) 553-2121

Specialties & licences

Infectious Disease Physician (primary) Taxonomy 207RI0200X · Licence N7411 (AR)

Record details

NPI number1568459451
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedOctober 5, 2005
Last updated in NPPESOctober 18, 2024
Certification dateOctober 18, 2024

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINFECTIOUS DISEASE
Also practisesINTERNAL MEDICINE
Medical schoolUNIVERSITY OF MARYLAND SCHOOL OF MEDICINE
Graduated 1982 (44 years in practice)
Group practice Mercy Clinic Fort Smith Communities — 350 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients30
Services billed 214 a service is one billed item, such as a visit, a test or a procedure
Average patient age71

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $780 24 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Mercy Clinic Fort Smith Communities

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 350 clinicians in the practice; 12 are shown here.

Other providers in Fort Smith