CYNTHIA ASHBROOK
NPI 1386786408
Allergy & Immunology in Walnut Creek, CA
About Cynthia Ashbrook NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
CYNTHIA ASHBROOK (NPI 1386786408) is an individual allergy & immunology provider in Walnut Creek, California, licensed in California (G63996) and active in the NPI registry since February 2007. She is enrolled in Medicare PECOS and is a graduate of University Of South Carolina School Of Medicine (1987).
NPPES Registry Identity
Specialties & Licenses
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Cynthia Ashbrook is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignment
Medicare enrollment records show Cynthia Ashbrook reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Walnut Creek, CA 94597
- Reassigned Medicare billing, California enrollment
- 650 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Areas of Expertise CMS Part B claims
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Reported Quality Measures
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
WALNUT CREEK, CA 94597
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Cynthia Ashbrook's NPI number?
The NPI number for Cynthia Ashbrook is 1386786408. It was assigned to this individual provider in the NPPES registry on February 13, 2007.
Where is Cynthia Ashbrook located?
Cynthia Ashbrook practices at 1450 Treat Blvd Suite 300, Walnut Creek, CA 94597. The listed phone number is (925) 952-2888.
What is Cynthia Ashbrook's specialty?
The primary specialty registered for this NPI is Allergy & Immunology with taxonomy code 207K00000X.
Is Cynthia Ashbrook enrolled in Medicare?
Yes. Cynthia Ashbrook is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organization bills Medicare for Cynthia Ashbrook's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Cynthia Ashbrook reassigns Medicare benefits to John Muir Physician Network (Walnut Creek, CA). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Cynthia Ashbrook's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Cynthia Ashbrook was last updated on May 9, 2017. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Cynthia Ashbrook · NPI 1386786408
Allergy & Immunology physician in Walnut Creek, California. Individual provider, active in the CMS NPPES registry since February 13, 2007.
## Identity
- **NPI:** 1386786408 (Entity type: Individual)
- **Enumerated:** February 13, 2007
- **Primary specialty:** Allergy & Immunology · taxonomy 207K00000X
- **State license:** G63996 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 1450 TREAT BLVD, SUITE 300, Walnut Creek, CA 94597-2168
- **Phone:** (925) 952-2888
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** John Muir Physician Network (NPI 1841407665, Walnut Creek, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of South Carolina School Of Medicine, class of 1987
## Record status
- **NPPES last updated:** May 9, 2017
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Source: [NPI Profile](https://npiprofile.com/npi/1386786408) · Data from the CMS NPPES public registry.