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

Robert Ryn Johnson, MD

Individual provider Therapeutic Radiology Physician · NPI 1598942781

Robert Ryn Johnson, MD is a Radiation Oncology in San Luis Obispo, California. Graduated from Cincinnati College of Medicine and Surgery in 2007, 19 years ago. Practices with Sutter Bay Medical Foundation, a 3,762-clinician group, accepts Medicare assignment and offers telehealth. Licensed in California.

Years since qualifying
19
Trained at
Cincinnati College of Medicine and Surgery
Licensed in
CA
In the registry since
2008
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

100 Casa St Ste C
San Luis Obispo, CA 93405-8804
Phone: (805) 541-1932
Fax: (805) 541-1653
Show map & directions

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

Specialties & licences

Therapeutic Radiology Physician (primary) Taxonomy 2085R0203X · Licence A121032 (CA)

Record details

NPI number1598942781
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedJanuary 30, 2008
Last updated in NPPESOctober 21, 2022
Certification dateOctober 21, 2022

Medicare enrollment

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

Medicare specialtyRADIATION ONCOLOGY
Medical schoolCINCINNATI COLLEGE OF MEDICINE AND SURGERY
Graduated 2007 (19 years in practice)
Group practice Sutter Bay Medical Foundation — 3762 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations4 on file with Medicare