Quick answers
- Which hospitals does Jonathan Posin work at?
- Medicare's official clinician data lists Jonathan Posin at 5 hospitals: Contra Costa Regional Medical Center, John Muir Medical Center - Concord Campus, John Muir Medical Center - Walnut Creek Campus, San Ramon Regional Medical Center and Zuckerberg San Francisco General Hosp & Trauma Ctr. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Jonathan Posin see patients?
- Medicare's clinician data lists 4 practice locations, including San Francisco, CA, Walnut Creek, CA and Lafayette, CA. Call before your visit to confirm the address.
- What is Jonathan Posin's specialty?
- Medicare lists Diagnostic Radiology as the primary specialty.
- Does Jonathan Posin accept Medicare assignment?
- Medicare's clinician data says Jonathan Posin may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is the phone number for Jonathan Posin?
- (628) 206-5871, as listed in official Medicare / NPI Registry data.
- What is Jonathan Posin's NPI number?
- 1396780425. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Jonathan Posin works
Medicare's Facility Affiliation Data lists Jonathan Posin at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Contra Costa Regional Medical CenterMartinez, CA · Acute Care Hospital · CCN 050276
- John Muir Medical Center - Concord CampusConcord, CA · Acute Care Hospital · CCN 050496
- John Muir Medical Center - Walnut Creek CampusWalnut Creek, CA · Acute Care Hospital · CCN 050180
- San Ramon Regional Medical CenterSan Ramon, CA · Acute Care Hospital · CCN 050689
- Zuckerberg San Francisco General Hosp & Trauma CtrSan Francisco, CA · Acute Care Hospital · CCN 050228
Practice locations
Addresses where Jonathan Posin is enrolled with Medicare (CMS data updated 2026-10-02).
- 1001 Potrero AveSan Francisco, CA 94110 (628) 206‑5871
- 1601 Ygnacio Valley RdWalnut Creek, CA 94598 (925) 295‑1545
- 1601 Ygnacio Vly RdWalnut Creek, CA 94596 (925) 939‑3000
- 3369 Hermosa WayLafayette, CA 94549 (925) 296‑7150
Group practices
Medicare enrollment lists Jonathan Posin as a member of these groups (CMS data updated 2026-10-02).
- University of California SFGH Medical Group587 clinicians in the group
- Bay Imaging Consultants Medical Group Inc146 clinicians in the group
- John Muir Trauma Physicians Billing Service113 clinicians in the group
- John Muir Magnetic Imaging Center57 clinicians in the group
Specialties
- Diagnostic Radiologyprimary
Other radiologists in San Francisco
Clinicians with the same Medicare primary specialty in San Francisco, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Boston University School Of Medicine |
| Graduation year | 1979 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1396780425 |
| 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