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

Dr. Gregory Tierney, PHD

Individual provider Clinical Psychologist · NPI 1609949809

Dr. Gregory Tierney, PHD is a Clinical Psychologist in Sycamore, Illinois. Licensed in Illinois. Registered with an NPI since 2006.

Licensed in
IL
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

920 S Prairie Dr Ste F
Sycamore, IL 60178
Phone: (815) 899-0339
Fax: (815) 899-2098
Show map & directions

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

Specialties & licences

Clinical Psychologist (primary) Taxonomy 103TC0700X · Licence 071.006674 (IL)

Record details

NPI number1609949809
Entity typeIndividual (Type 1)
GenderMale
Credentials PHD
Sole proprietorNo
NPI enumeratedNovember 16, 2006
Last updated in NPPESMay 23, 2018

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