Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Barbara L. Johnston, PH.D.
Psychologist in Martinez, CA · enumerated 2010.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1982924965
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Registry record
Entity type Individual (Type 1)
Name Barbara L. Johnston
Credential PH.D.
Sex Female
Practice address 41 Wanda Way, Martinez, CA, 94553
Phone (925) 229-3162
Enumeration date Jun 1, 2010
Last updated in NPPES Oct 25, 2010
Taxonomy & licenses
PHD · Doctor of Philosophy: A doctoral degree; in healthcare often held by clinical psychologists and researchers.
About the PHD credential
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.
Frequently asked questions
Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.
What specialty is Barbara Johnston?
Barbara Johnston is registered in NPPES with the primary taxonomy of Psychologist. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-10-25.