Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

DUNCAN PATRICK O'MAHONY PSYCHOLOGIST
NPI 1821963869
Psychologist in Issaquah, WA

Active since October 08, 2025
195 NE GILMAN BLVD STE 100, ISSAQUAH, WA 98027(425) 295-7697 Get Directions Write a Review

NPPES record last updated: September 9, 2026. Verified against the NPPES registry weekly; last sync: September 20, 2026.

Record update history: Sep 9, 2026, Oct 8, 2025 (2 updates tracked since 2025).

About Duncan Patrick O'mahony Psychologist NPPES

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

DUNCAN PATRICK O'MAHONY PSYCHOLOGIST (NPI 1821963869) is an individual psychologist in Issaquah, Washington, licensed in Washington (PSYA.PG.7O165412) and active in the NPI registry since October 2025.

NPPES Registry Identity

NPI1821963869
Entity TypeIndividualMale
Primary Taxonomy103T00000X
Provider Legal NameDUNCAN PATRICK O'MAHONYCredential: PSYCHOLOGIST
Location Address195 NE GILMAN BLVD STE 100Issaquah, WA 98027-2940
Mailing Address8823 Holly Dr Apt 505Everett, WA 98208-1843 · (425) 295-7697
Sole ProprietorYes
Enumeration DateOctober 8, 2025
Last NPPES UpdateSeptember 9, 20262 updates tracked since enumeration
NPPES CertifiedSeptember 9, 2026
✔ NPI 1821963869 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 WA · PSYA.PG.7O165412
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 ListedCounselor · Mental HealthTaxonomy 101YM0800X · License MHCLH61523993 (WA)
195 NE GILMAN BLVD STE 100, Issaquah, WA 98027

Other Providers at the Same Location NPPES 20

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

Psychologist (Clinical)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027
Counselor (Mental Health)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027
Counselor (Mental Health)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027
Counselor (Mental Health)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027
Counselor (Mental Health)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027
Counselor (Mental Health)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027
Counselor (Mental Health)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027
Counselor (Mental Health)
195 NE GILMAN BLVD STE 100
ISSAQUAH, WA 98027

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 Duncan O'mahony's NPI number?

The NPI number for Duncan O'mahony is 1821963869. It was assigned to this individual provider in the NPPES registry on October 8, 2025.

Where is Duncan O'mahony located?

Duncan O'mahony practices at 195 NE Gilman Blvd Ste 100, Issaquah, WA 98027. The listed phone number is (425) 295-7697.

What is Duncan O'mahony'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 Duncan O'mahony was last updated on September 9, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 15 days 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.