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

Mark A Thomas, MD

Individual provider Internal Medicine Physician · NPI 1629086277

Mark A Thomas, MD practises Internal Medicine in Topeka, Kansas. Qualified in 1990, 36 years ago. Practices with Cotton-O'Neil Clinic Revocable Trust, a 658-clinician group and accepts Medicare assignment. Licensed in Kansas.

Years since qualifying
36
Licensed in
KS
In the registry since
2006
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

4409 SW Shenandoah Rd
Topeka, KS 66610-1678
Phone: (785) 554-6259
Show map & directions

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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 04-25848 (KS)

Record details

NPI number1629086277
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedAugust 3, 2006
Last updated in NPPESMay 1, 2026
Certification dateMay 1, 2026

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolOTHER
Graduated 1990 (36 years in practice)
Group practice Cotton-O'Neil Clinic Revocable Trust — 658 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Removal or shaving of skin growth 1–10 times

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

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 patients554
Services billed 5,324 a service is one billed item, such as a visit, a test or a procedure
Average patient age75

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.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

  • Stormont Vail Hospital Hospital · Topeka, KS
  • University Of Kansas Health System - St Francis Campus Hospital · Topeka, KS
  • Midland Care Home Health Home health agency · Topeka, KS

Colleagues at Cotton-O'Neil Clinic Revocable Trust

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 658 clinicians in the practice; 12 are shown here.

Other providers in Topeka