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

Dr. Mark Thomas Day, DO

Individual provider Internal Medicine Physician · NPI 1225492796

Dr. Mark Thomas Day, DO is an Internal Medicine in Lebanon, Oregon. Graduated from Des Moines University of Osteopathic Medicine and Health Sciences in 2017, 9 years ago. Practices with Legacy Good Samaritan Hospital and Medical Center, a 192-clinician group, works from 2 locations, accepts Medicare assignment and offers telehealth. Licensed in Oregon.

Years since qualifying
9
Trained at
Des Moines University of Osteopathic Medicine and Health Sciences
Licensed in
OR
In the registry since
2016
Specialties on file
3
What do these letters mean?
DO — Doctor of Osteopathic Medicine
A fully licensed physician, trained like an MD with additional musculoskeletal training. Equivalent practice rights in all 50 states.

See every abbreviation used in this directory →

Practice location Address checks out

525 N Santiam Hwy
Lebanon, OR 97355-4363
Phone: (541) 258-2101
Show map & directions

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

Additional practice locations (1)

  • 3600 Nw Samaritan Dr, Corvallis, OR 97330-3737 — (541) 768-4906

Specialties & licences

Cardiovascular Disease Physician (primary) Taxonomy 207RC0000X · Licence DO197880 (OR)
Internal Medicine Physician Taxonomy 207R00000X · Licence 182616 (OR)
Student in an Organized Health Care Education/Training Program Taxonomy 390200000X

Record details

NPI number1225492796
Entity typeIndividual (Type 1)
GenderMale
Credentials DO
Sole proprietorNo
NPI enumeratedApril 11, 2016
Last updated in NPPESFebruary 28, 2023
Certification dateFebruary 28, 2023
Mailing addressPo Box 1193, Corvallis, OR 97339-1193

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolDES MOINES UNIVERSITY OF OSTEOPATHIC MEDICINE AND HEALTH SCIENCES
Graduated 2017 (9 years in practice)
Group practice Legacy Good Samaritan Hospital And Medical Center — 192 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations6 on file with Medicare

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