Quick answers
- Which hospitals does Cynthia Ashbrook work at?
- Medicare's official clinician data lists Cynthia Ashbrook at 2 hospitals: John Muir Medical Center - Concord Campus and John Muir Medical Center - Walnut Creek Campus. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Cynthia Ashbrook see patients?
- Medicare's clinician data lists 1 practice location in Walnut Creek, CA. Call before your visit to confirm the address.
- What is Cynthia Ashbrook's specialty?
- Medicare lists Family Practice as the primary specialty.
- Does Cynthia Ashbrook accept Medicare assignment?
- Yes. Medicare's clinician data says Cynthia Ashbrook 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 Cynthia Ashbrook?
- (925) 296-9000, as listed in official Medicare / NPI Registry data.
- What is Cynthia Ashbrook's NPI number?
- 1386786408. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Cynthia Ashbrook works
Medicare's Facility Affiliation Data lists Cynthia Ashbrook at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- 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
Practice locations
Addresses where Cynthia Ashbrook is enrolled with Medicare (CMS data updated 2026-10-02).
- 1450 Treat Blvd, Suite 160Walnut Creek, CA 94597 (925) 296‑9000
Group practices
Medicare enrollment lists Cynthia Ashbrook as a member of this group (CMS data updated 2026-10-02).
- John Muir Physician Network494 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Walnut Creek
Clinicians with the same Medicare primary specialty in Walnut Creek, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of South Carolina School Of Medicine |
| Graduation year | 1987 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1386786408 |
| 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