Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
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Dr. Mary Dianne Plummer Loudon, PHD

Individual provider Clinical Psychologist · NPI 1821318171

Dr. Mary Dianne Plummer Loudon, PHD is a Clinical Psychologist in Seattle, Washington. Practices as a sole proprietor. Licensed in Washington.

Licensed in
WA
In the registry since
2010
Specialties on file
2
What do these letters mean?
PHD — Doctor of Philosophy
A research doctorate. In healthcare it usually sits alongside a clinical licence.

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Practice location Address checks out

1700 Westlake Ave N Ste 400
Seattle, WA 98109-6263
Phone: (206) 769-2052
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Mental Health Counselor (primary) Taxonomy 101YM0800X · Licence PY60063635 (WA)
Clinical Psychologist Taxonomy 103TC0700X · Licence PY60063635 (WA)

Record details

NPI number1821318171
Entity typeIndividual (Type 1)
GenderFemale
Credentials PHD
Sole proprietorYes
NPI enumeratedJune 9, 2010
Last updated in NPPESAugust 24, 2021
Certification dateAugust 24, 2021

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