Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Mark Andrew Walshauser, MD

Individual provider Internal Medicine Physician · NPI 1306020664

Mark Andrew Walshauser, MD is a Hematology/Oncology in O Fallon, Illinois. Qualified in 2006, 20 years ago. Practices with Cancer Care Specialists of Central Illinois SC, a 28-clinician group, works from 3 locations, accepts Medicare assignment and offers telehealth. Licensed in Illinois and Missouri.

Years since qualifying
20
Licensed in
IL, MO
In the registry since
2007
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

321 Regency Park Ste 100
O Fallon, IL 62269-1887
Phone: (618) 416-7970
Fax: (618) 416-7971
Show map & directions

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

Additional practice locations (2)

  • 12860 Troxler Ave Ste 135, Highland, IL 62249-2898 — (618) 416-7970
  • Broadway Plaza Suite 1, Sparta, IL 62286-1800 — (618) 416-7970

Specialties & licences

Hematology & Oncology Physician (primary) Taxonomy 207RH0003X · Licence 036128331 (IL)
Internal Medicine Physician Taxonomy 207R00000X · Licence 2010024540 (MO)

Record details

NPI number1306020664
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedDecember 21, 2007
Last updated in NPPESDecember 12, 2023
Certification dateDecember 8, 2023
Mailing addressPo Box 25228, Decatur, IL 62525-5228

Medicare enrollment

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

Medicare specialtyHEMATOLOGY/ONCOLOGY
Medical schoolOTHER
Graduated 2006 (20 years in practice)
Group practice Cancer Care Specialists Of Central Illinois Sc — 28 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

Other providers in O Fallon