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

Dr. Mark A Williams, PHD

Individual provider Clinical Neuropsychologist · NPI 1699922112

Dr. Mark A Williams, PHD is a Clinical Neuropsychologist in Patton, California. Registered with an NPI since 2008.

In the registry since
2008
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.

See every abbreviation used in this directory →

Practice location Address checks out

3102 E Highland Avenue Medical Staff Ofc
Patton, CA 92369
Phone: (909) 425-7679
Fax: (909) 425-6635
Show map & directions

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

Specialties & licences

Clinical Neuropsychologist (primary) Taxonomy 103G00000X
Forensic Psychologist Taxonomy 103TF0200X

Record details

NPI number1699922112
Entity typeIndividual (Type 1)
GenderMale
Credentials PHD
Sole proprietorNo
NPI enumeratedAugust 27, 2008
Last updated in NPPESJuly 29, 2013
Mailing address3102 E. Highland Avenue, Medical Staff Office, Patton, CA 92369

Other providers in Patton