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

Mark Gregory Kiefner, PHD

Individual provider Clinical Neuropsychologist · NPI 1346457017

Mark Gregory Kiefner, PHD is a Clinical Neuropsychologist in Portland, Maine. Licensed in Maine. Registered with an NPI since 2007.

Licensed in
ME
In the registry since
2007
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 →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

26 Portland St
Portland, ME 04101
Phone: (207) 761-8402
Fax: (207) 761-8405
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

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

Specialties & licences

Clinical Neuropsychologist (primary) Taxonomy 103G00000X · Licence PS815 (ME)

Record details

NPI number1346457017
Entity typeIndividual (Type 1)
GenderMale
Credentials PHD
Sole proprietorNo
NPI enumeratedMay 16, 2007
Last updated in NPPESJuly 8, 2007
Mailing addressPo Box 8600, Portland, ME 04104

Other providers in Portland