Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Mark Summerson, PHD, LLC

Organization Psychologist · NPI 1447604509

Mark Summerson, PHD, LLC is a Psychologist in Pullman, Washington. Licensed in Washington. Registered with an NPI since 2016.

Licensed in
WA
In the registry since
2016
What do these letters mean?
LLC — Limited liability company
A form of business registration, not a clinical qualification.

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Practice location Address checks out

254 E Main St Ste 226
Pullman, WA 99163-2678
Phone: (509) 330-5456
Fax: (509) 561-6229
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Psychologist (primary) Taxonomy 103T00000X · Licence PY00002258 (WA)

Record details

NPI number1447604509
Entity typeOrganization (Type 2)
Organization subpartNo
Authorized official Mark Summerson — Psychologist · (509) 330-5456
NPI enumeratedApril 14, 2016
Last updated in NPPESApril 14, 2016
Mailing address254 E Main St, Suite 226, Pullman, WA 99163-2678

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