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

Stephen Louis Walston, MD

Individual provider Internal Medicine Physician · NPI 1578887519

Stephen Louis Walston, MD is an Internal Medicine in Mercer Island, Washington. Graduated from University of Texas Medical School at Houston in 2010, 16 years ago. Practices with Select Outpatient Services Inc, a 790-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Washington.

Years since qualifying
16
Trained at
University of Texas Medical School at Houston
Licensed in
WA
In the registry since
2010
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

3236 78th Ave SE Ste 200
Mercer Island, WA 98040-3500
Phone: (206) 386-9500
Fax: (206) 386-9605
Show map & directions

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

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence MD60423761 (WA)

Record details

NPI number1578887519
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedMarch 19, 2010
Last updated in NPPESNovember 11, 2021
Certification dateNovember 11, 2021

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolUNIVERSITY OF TEXAS MEDICAL SCHOOL AT HOUSTON
Graduated 2010 (16 years in practice)
Group practice Select Outpatient Services Inc — 790 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations3 on file with Medicare

Other providers in Mercer Island