Frank Castillo, NP
Nurse Practitioner · Walnut Creek, CA
Frank Castillo, NP is a nurse practitioner with a practice address in Walnut Creek, California, and NPI 1639623770, issued on Aug 5, 2016. Check the license (California 95004634, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Frank Castillo
- Credential
- NP
- Primary taxonomy
- Nurse Practitioner 363L00000X
- License number
- 95004634 CA
Self-reported in NPPES; status is on the state search - Practice location
- 100 N Wiget LN Ste 290, Walnut Creek, CA 94598
- Phone
- (925) 937-7740
- Enumerated
- Aug 5, 2016
- Record last updated
- Sep 22, 2025
- Medicare enrollment
- Enrolled (PECOS I20170307001368); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest nurse practitioner records → All 8,223 in California → Look up another NPI →
Also registered at 100 N Wiget LN Ste 290
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Frank Castillo in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 95004634Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average nurse practitioner in 2024
18 Medicare Part D claims, against an average of 1,109 among the 54,319 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.
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.
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).
Frank Castillo among 8,223 nurse practitioner records in California
Frank Castillo, NP is one of 8,223 nurse practitioner records with a practice address in California. 65% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2016, is newer than 48% of them.
- NPI issued2016 · 48% of these records are older, 48% newer
- In a Medicare fileYes · 65% of these records are
- In the CMS Doctors and Clinicians fileYes · 42% of these records are
- Graduated2016 · median 2017 among the 3,425 with a school on file
- Record last updated2025 · 45% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363L00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
70 nurse practitioner records list a practice address in Walnut Creek
They are 70 of the 6,170 NPPES records with a practice address in Walnut Creek, and 8,223 nurse practitioner records in California.
All 8,223 in California → Every provider in Walnut Creek → Nurse Practitioner nationwide →
The 8 nurse practitioner records with the nearest ZIP codes
- Sarah Berg, NPWalnut Creek, CA 945981427062975
- Emily Brama, RN, MSN, FNP, NP-CWalnut Creek, CA 945981952696684
- Sarah Buenviaje, M.S.N., O.N.P.Walnut Creek, CA 945981588716971
- Kathleen Fitterer, N.P.Walnut Creek, CA 945981649439126
- Allison Hanson, NPWalnut Creek, CA 945981376537589
- Amy Inouye, NPWalnut Creek, CA 945981780740332
- Olga Izmaylova, NPWalnut Creek, CA 945981568647543
- Leah Juhle, MSN, NP-CWalnut Creek, CA 945981255570750
Common questions
What is Frank Castillo, NP's NPI number?
Frank Castillo, NP's National Provider Identifier (NPI) is 1639623770, issued on Aug 5, 2016. An NPI identifies a provider in billing; it is not a license.
Where is Frank Castillo, NP located?
The NPPES record lists a practice address at 100 N Wiget LN Ste 290, Walnut Creek, CA, 94598. Phone: (925) 937-7740. Providers update this record themselves, so call before visiting.
How can I verify Frank Castillo, NP's license?
NPPES lists California license number 95004634, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Frank Castillo, NP prescribe under Medicare Part D?
In 2024, Frank Castillo, NP had 18 Medicare Part D claims; the average among nurse practitioner prescribers was 1,109. Part D covers Medicare prescriptions only.
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.