Quick answers
- Which hospitals does John B. Colby work at?
- Medicare's official clinician data lists John B. Colby at 5 hospitals: Marinhealth Medical Center, Novato Community Hospital, Providence Santa Rosa Memorial Hospital, Sonoma Valley Hospital and UCSF Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John B. Colby see patients?
- Medicare's clinician data lists 9 practice locations, including Greenbrae, CA, Santa Rosa, CA and Novato, CA. Call before your visit to confirm the address.
- What is John B. Colby's specialty?
- Medicare lists Diagnostic Radiology as the primary specialty, and also Interventional Radiology.
- Does John B. Colby accept Medicare assignment?
- Yes. Medicare's clinician data says John B. Colby accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for John B. Colby?
- (415) 925-7301, as listed in official Medicare / NPI Registry data.
- What is John B. Colby's NPI number?
- 1700205374. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where John B. Colby works
Medicare's Facility Affiliation Data lists John B. Colby at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Marinhealth Medical CenterGreenbrae, CA · Acute Care Hospital · CCN 050360
- Novato Community HospitalNovato, CA · Acute Care Hospital · CCN 050131
- Providence Santa Rosa Memorial HospitalSanta Rosa, CA · Acute Care Hospital · CCN 050174
- Sonoma Valley HospitalSonoma, CA · Acute Care Hospital · CCN 050090
- UCSF Medical CenterSan Francisco, CA · Acute Care Hospital · CCN 050454
Practice locations
Addresses where John B. Colby is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 9; the Medicare profile lists all.
- 1240 S Eliseo Dr, Suite 103Greenbrae, CA 94904 (415) 925‑7301
- 1260 S Elideo DrGreenbrae, CA 94904
- 1350 S Elideo DrGreenbrae, CA 94904
- 1701 4th St, Suite 120Santa Rosa, CA 95404 (707) 523‑7025
- 180 Rowland WayNovato, CA 94945 (415) 209‑1500
Group practices
Medicare enrollment lists John B. Colby as a member of these groups (CMS data updated 2026-10-02).
- California Advanced Imaging Medical Associates Inc88 clinicians in the group
- Prima Medical Foundation31 clinicians in the group
Specialties
- Diagnostic Radiologyprimary
- Interventional Radiologyalso
Other radiologists in Greenbrae
Clinicians with the same Medicare primary specialty in Greenbrae, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, Geffen School Of Medicine |
| Graduation year | 2014 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1700205374 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians