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

Dr. William Arl Hahnstadt, PHD

Individual provider Rehabilitation Psychologist · NPI 1659442804

Dr. William Arl Hahnstadt, PHD is a Rehabilitation Psychologist in Missoula, Montana. Practices as a sole proprietor. Licensed in Montana.

Licensed in
MT
In the registry since
2006
What do these letters mean?
PHD — Doctor of Philosophy
A research doctorate. In healthcare it usually sits alongside a clinical licence.

See every abbreviation used in this directory →

Practice location Address checks out

4850 Spurgin Rd
Missoula, MT 59804-4510
Phone: (406) 549-9475
Show map & directions

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

Specialties & licences

Rehabilitation Psychologist (primary) Taxonomy 103TR0400X · Licence 171 (MT)

Record details

NPI number1659442804
Entity typeIndividual (Type 1)
GenderMale
Credentials PHD
Sole proprietorYes
NPI enumeratedNovember 10, 2006
Last updated in NPPESAugust 24, 2020
Certification dateAugust 24, 2020