Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
Matthew Bruce Duff
Psychologist in Issaquah, WA · enumerated 2026.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1023912672
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Registry record
Entity type Individual (Type 1)
Name Matthew Bruce Duff
Sex Male
Practice address 195 Ne Gilman Blvd Ste 100, Issaquah, WA, 98027
Phone (425) 295-7697
Enumeration date Oct 6, 2026
Last updated in NPPES Oct 6, 2026
Taxonomy & licenses
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
What is the NPI number for Matthew Duff?
The National Provider Identifier (NPI) for Matthew Duff is 1023912672, a Type 1 (individual) record in the CMS NPPES registry.
Where does Matthew Duff practice?
The practice location on file with NPPES is in Issaquah, WA. Providers can have multiple locations; NPPES lists the primary practice address.
Other providers at this practice address
Browse all → Nathaniel Metzger Mental Health Counselor · Issaquah, WA NPI 1780093385 Lisa Galeucia Mental Health Counselor · Issaquah, WA NPI 1144629213 Antony Narciso Mental Health Counselor · Issaquah, WA NPI 1417308479 Kelley Molinari Marriage & Family Therapist · Issaquah, WA NPI 1679028492 Anna Schoner Mental Health Counselor · Issaquah, WA NPI 1265963607 Sophia Goldberg Mental Health Counselor · Issaquah, WA NPI 1942729074 Zoraida Price Mental Health Counselor · Issaquah, WA NPI 1124584511 Alexandra Blohowiak Mental Health Counselor · Issaquah, WA NPI 1780246702
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-10-06.