Mark Andrew Walshauser, M.D.
Mark Andrew Walshauser is a Hematology & Oncology specialist based in O Fallon, IL with over 20 years of clinical experience. Offers virtual telehealth visits.
Mark Andrew Walshauser, M.D. has practiced internal medicine for 20+ years, working in group practice. With 20+ years of experience, he has been practicing in the O Fallon area. Among his Medicare patients, common conditions include hypertension, high cholesterol, and arthritis (per CMS data).
Older · 893dNPPES updated 2023-12-12 · verify NPI on CMS · Verify license at Illinois Department of Financial & Professional Regulation — Medical
Contact & Location
Practice Location
321 Regency Park Ste 100, O Fallon, IL 62269-1887
What This Doctor Treats Most
Based on Medicare claims data — here's what patients commonly see this doctor for
Based on Medicare data, this doctor primarily manages Hypertension, High Cholesterol, and Arthritis.
High blood pressure — a leading risk factor for heart disease and stroke
Elevated cholesterol or triglycerides that increase heart disease risk
Joint inflammation causing pain, swelling, and stiffness
Diseases involving abnormal cell growth with potential to spread to other body parts
A condition where the body cannot properly regulate blood sugar levels
Gradual loss of kidney function over time, often linked to diabetes or hypertension
Reduced blood flow to the heart muscle, commonly known as coronary artery disease
Chronic Obstructive Pulmonary Disease — a group of lung diseases that block airflow
Percentage of this provider's Medicare patients diagnosed with each condition. Source: CMS Utilization Data.
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Background & Specialty
Education, training, and specialty classification from CMS NPPES and Medicare records.
Board certified · Dec 7, 2023
Self-reported via NPPES
20 years in practice
Experienced
An internist doctor of osteopathy that specializes in the treatment of the combination of hematology and oncology disorders. A doctor of osteopathy that is board eligible/certified by the American Osteopathic Board of Internal Medicine WAS able to obtain a Certificate of Special Qualifications in the field of Hematology and Oncology. The Certificate is NO longer offered.
Taxonomy: 207RH0003X
Mailing address
Po Box 25228, Decatur, IL 62525-5228
Differs from practice location
Virtual Hematology & Oncology Care With Mark Andrew Walshauser
NPPES records indicate this provider offers telehealth services. Contact the office to confirm availability and scheduling.
Schedule a virtual visit with Mark Andrew Walshauser for blood pressure monitoring, cholesterol management, arthritis follow-ups — no travel to O Fallon required. The office sends a secure video link before your appointment. Most visits take 15–30 minutes.
Frequently Asked Questions
Common questions about Mark Andrew Walshauser
NPI records show Dr. Walshauser as active with telehealth listed in O Fallon, IL. NPI status alone doesn't confirm open availability — call the office to confirm. Phone: (618) 416-7970.
Sourced from CMS NPPES · OIG LEIE · CMS Physician Comparator. See Data Methodology.
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Medical Disclaimer: NPI Telehealth is a provider directory for informational purposes only. This page does not constitute medical advice, diagnosis, or treatment recommendations. Provider data is sourced from the CMS NPPES federal registry and public Medicare datasets. NPI Telehealth does not verify clinical qualifications beyond federal records. Data may not reflect real-time availability — always contact the provider's office directly to confirm details before seeking care.
Contact Mark Andrew Walshauser
Practice Location
321 Regency Park Ste 100, O Fallon, IL 62269-1887
Mailing Address
Po Box 25228, Decatur, IL 62525-5228
This is a provider directory. Contact the office directly to schedule appointments.
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