Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Cynthia Ashbrook

Individual provider Allergy & Immunology Physician · NPI 1386786408

Cynthia Ashbrook is registered under Family Practice in Walnut Creek, California. Graduated from University of South Carolina School of Medicine in 1987, 39 years ago. Practices with John Muir Physician Network, a 486-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
39
Trained at
University of South Carolina School of Medicine
Licensed in
CA
In the registry since
2007
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Practice location Address checks out

1450 Treat Blvd Ste 300
Walnut Creek, CA 94597-2168
Phone: (925) 952-2888
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Allergy & Immunology Physician (primary) Taxonomy 207K00000X · Licence G63996 (CA)

Record details

NPI number1386786408
Entity typeIndividual (Type 1)
GenderFemale
Sole proprietorYes
NPI enumeratedFebruary 13, 2007
Last updated in NPPESMay 9, 2017

Medicare enrollment

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

Medicare specialtyFAMILY PRACTICE
Medical schoolUNIVERSITY OF SOUTH CAROLINA SCHOOL OF MEDICINE
Graduated 1987 (39 years in practice)
Group practice John Muir Physician Network — 486 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients43
Services billed 75 a service is one billed item, such as a visit, a test or a procedure
Average patient age76

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

Colleagues at John Muir Physician Network

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 486 clinicians in the practice; 12 are shown here.

Other providers in Walnut Creek