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

Dr. John Benjamin Colby, MD, PHD

Individual provider Neuroradiology Physician · NPI 1700205374

Dr. John Benjamin Colby, MD, PHD is a Diagnostic Radiology in Greenbrae, California. Graduated from University of California, Geffen School of Medicine in 2014, 12 years ago. Practices with Prima Medical Foundation, a 29-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
12
Trained at
University of California, Geffen School of Medicine
Licensed in
CA
In the registry since
2014
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.
PHD — Doctor of Philosophy
A research doctorate. In healthcare it usually sits alongside a clinical licence.

See every abbreviation used in this directory →

Practice location Address checks out

250 Bon Air Rd
Greenbrae, CA 94904-1702
Phone: (415) 925-7301
Show map & directions

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

Specialties & licences

Neuroradiology Physician (primary) Taxonomy 2085N0700X · Licence A139185 (CA)

Record details

NPI number1700205374
Entity typeIndividual (Type 1)
GenderMale
Credentials MD , PHD
Sole proprietorNo
NPI enumeratedApril 10, 2014
Last updated in NPPESJuly 1, 2020
Certification dateJuly 1, 2020
Mailing address500 Redwood Blvd Ste 300, Novato, CA 94947-6921

Medicare enrollment

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

Medicare specialtyDIAGNOSTIC RADIOLOGY
Also practisesINTERVENTIONAL RADIOLOGY
Medical schoolUNIVERSITY OF CALIFORNIA, GEFFEN SCHOOL OF MEDICINE
Graduated 2014 (12 years in practice)
Group practice Prima Medical Foundation — 29 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations8 on file with Medicare

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