Mariela M. Costello, PSY.D.
Clinical Psychologist · Los Altos, CA
Mariela M. Costello, PSY.D. is a clinical psychologist with a practice address in Los Altos, California, and NPI 1801145727, issued on Sep 6, 2012. Check the license (California PSY23277, as entered in NPPES) with the California board that licenses this profession; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- Mariela M. Costello
- Credential
- PSY.D.
- Primary taxonomy
- Clinical Psychologist 103TC0700X
- License number
- PSY23277 CA
Self-reported in NPPES; status is on the state search - Practice location
- 919 Fremont Ave, Los Altos, CA 95020
- Phone
- (408) 220-3268
- Enumerated
- Sep 6, 2012
- Record last updated
- Oct 2, 2018 (not updated in 8 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
Also registered at 919 Fremont Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Judy Smith, PH.D.Clinical Psychologist1770017063
- Jennifer Zumarraga, M.D.Child & Adolescent Psychiatry Physician1518987601
- Ximena Zurita, PH.D.Psychologist1356566400
Verify Mariela M. Costello in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license PSY23277Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
36 clinical psychologist records list a practice address in Los Altos
They are 36 of the 718 NPPES records with a practice address in Los Altos, and 12,647 clinical psychologist records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 36 in Los Altos → All 12,647 in California → Every provider in Los Altos →
Other clinical psychologist records in California
- Tanya Aaen, PH.D.Martinez, CA1477518561
- Jack Aamot, PSY.D.Napa, CA1770711210
- Brian Abary, PSY.DLos Angeles, CA1538354832
- Tatevik Abaryan, PH.D.Pacoima, CA1952682619
- Liana Abascal, PH.D.San Diego, CA1073740569
- Jessica Abdalla, PHDWalnut Creek, CA1558069211
- Mohamed Abdallah, PSY.DEl Centro, CA1912430851
- Megan Abdolrashidi, PSYDGilroy, CA1093293094
- Keri Abdullah, PH.D.San Diego, CA1699840587
- Qutayba Abdullatif, PH.D.Pasadena, CA1134667751
Common questions
What is Mariela M. Costello, PSY.D.'s NPI number?
Mariela M. Costello, PSY.D.'s National Provider Identifier (NPI) is 1801145727, issued on Sep 6, 2012. An NPI identifies a provider in billing; it is not a license.
Where is Mariela M. Costello, PSY.D. located?
The NPPES record lists a practice address at 919 Fremont Ave, Los Altos, CA, 95020. Phone: (408) 220-3268. Providers update this record themselves, so call before visiting.
How can I verify Mariela M. Costello, PSY.D.'s license?
NPPES lists California license number PSY23277, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity 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. 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.