DR. DIANE K. KOSTERS PH.D.
NPI 1902029275
Psychologist in Walnut Creek, CA

Active since April 11, 2007
43 QUAIL CT STE 213, WALNUT CREEK, CA 94596(925) 946-9660(925) 946-9660 Get Directions Write a Review

NPPES record last updated: September 11, 2025. Verified against the NPPES registry weekly; last sync: August 23, 2026.

About Dr. Diane K. Kosters Ph.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. DIANE K. KOSTERS PH.D. (NPI 1902029275) is an individual psychologist in Walnut Creek, California, licensed in California (PSY7055) and active in the NPI registry since April 2007.

NPPES Registry Identity

NPI1902029275
Entity TypeIndividualFemale
Primary Taxonomy103T00000X
Provider Legal NameDR. DIANE K. KOSTERSCredential: PH.D.
Location Address43 QUAIL CT STE 213Walnut Creek, CA 94596-8702
Mailing Address445 Lakewood CirWalnut Creek, CA 94598-4838 · (925) 946-9660 · Fax (925) 946-9660
Fax(925) 946-9660
Sole ProprietorYes
Enumeration DateApril 11, 2007
Last NPPES UpdateSeptember 11, 2025
NPI 1902029275 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

Primary SpecialtyPsychologistBehavioral Health & Social Service Providers
Taxonomy Code103T00000X
License Licensed in CA · PSY7055
Definition
A psychologist is an individual who is licensed to practice psychology which is defined as the observation, description, evaluation, interpretation, and modification of human behavior by the application of psychological principles, methods, and procedures, for the purpose of preventing or eliminating symptomatic, maladaptive, or undesired behavior and of enhancing interpersonal relationships, work and life adjustment, personal effectiveness, behavioral health, and mental health. The practice of psychology includes, but is not limited to, psychological testing and the evaluation or assessment of personal characteristics, such as intelligence, personality, abilities, interests, aptitudes, and neuropsychological functioning; counseling, psychoanalysis, psychotherapy, hypnosis, biofeedback, and behavior analysis and therapy; diagnosis and treatment of mental and emotional disorder or disability, alcoholism and substance abuse, disorders of habit or conduct, as well as of the psychological aspects of physical illness, accident, injury, or disability; and psycheducational evaluation, therapy, remediation, and consultation. Psychological services may be rendered to individuals, families, groups and the public.
Also ListedClinical NeuropsychologistTaxonomy 103G00000X · License PSY7055 (CA)

Other Providers at the Same Location NPPES

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

Social Worker (Clinical)
43 QUAIL CT STE 213
WALNUT CREEK, CA 94596

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 Diane Kosters's NPI number?

The NPI number for Diane Kosters is 1902029275. It was assigned to this individual provider in the NPPES registry on April 11, 2007.

Where is Diane Kosters located?

Diane Kosters practices at 43 Quail Ct Ste 213, Walnut Creek, CA 94596. The listed phone number is (925) 946-9660.

What is Diane Kosters's specialty?

The primary specialty registered for this NPI is Psychologist with taxonomy code 103T00000X.

When was this NPI record last updated?

The NPPES record for Diane Kosters was last updated on September 11, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 months 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.