Cynthia Ashbrook
Allergy & Immunology Physician · Walnut Creek, CA
Cynthia Ashbrook is an allergy & immunology physician with a practice address in Walnut Creek, California, and NPI 1386786408, issued on Feb 13, 2007. Check the license (California G63996, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Cynthia Ashbrook
- Primary taxonomy
- Allergy & Immunology Physician 207K00000X
- License number
- G63996 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1450 Treat Blvd, Walnut Creek, CA 94597
- Phone
- (925) 952-2888
- Enumerated
- Feb 13, 2007
- Record last updated
- May 9, 2017 (not updated in 9 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20170605002023); accepts Medicare assignment
- Medical or professional school
- University Of South Carolina School Of Medicine, 1987
- Entity
- Type 1 · individual
8 nearest allergy & immunology physician records → All 444 in California → Look up another NPI →
Also registered at 1450 Treat Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Devorah Ben-Zeev, M.D.Internal Medicine Physician1033160692
Verify Cynthia Ashbrook in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G63996Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
94% fewer Medicare Part D claims than the average allergy & immunology physician in 2024
41 Medicare Part D claims for 29 beneficiaries, against an average of 741 among the 2,899 providers of this specialty who prescribed in Part D.
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 85.7 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- John Muir Physician NetworkWalnut Creek, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Cynthia Ashbrook among 444 allergy & immunology physician records in California
Cynthia Ashbrook is one of 444 allergy & immunology physician records with a practice address in California. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 47% of them.
- NPI issued2007 · 47% of these records are older, 38% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1987 · median 2004 among the 281 with a school on file
- Record last updated2017 · 62% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207K00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy & Immunology Physician providers in California
There are 444 allergy & immunology physician records in California.
All 444 in California → Every provider in Walnut Creek → Allergy & Immunology Physician nationwide →
The 8 allergy & immunology physician records with the nearest ZIP codes
- Eric Chen, MDWalnut Creek, CA 945981558440222
- David Cook, MDWalnut Creek, CA 945981740282425
- David Fan, MDWalnut Creek, CA 945981619596152
- Karna Gendo, M.D.Walnut Creek, CA 945981720164536
- Ilisten Jones, M.D., M.P.H.Walnut Creek, CA 945981407148943
- Toral Kamdar, M.D.Walnut Creek, CA 945981073776555
- Barbara Karpel, MDWalnut Creek, CA 945981033111729
- Matthew Lodewick, MDWalnut Creek, CA 945981922091362
Common questions
What is Cynthia Ashbrook's NPI number?
Cynthia Ashbrook's National Provider Identifier (NPI) is 1386786408, issued on Feb 13, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Cynthia Ashbrook located?
The NPPES record lists a practice address at 1450 Treat Blvd, Walnut Creek, CA, 94597. Phone: (925) 952-2888. Providers update this record themselves, so call before visiting.
How can I verify Cynthia Ashbrook's license?
NPPES lists California license number G63996, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Cynthia Ashbrook prescribe under Medicare Part D?
In 2024, Cynthia Ashbrook had 41 Medicare Part D claims for 29 beneficiaries; the average among allergy & immunology physician prescribers was 741. Part D covers Medicare prescriptions only.
What is Cynthia Ashbrook's MIPS final score?
The 2023 MIPS final score is 85.7 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.