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

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Practice location Address checks out

920 S Prairie Dr Ste F
Sycamore, IL 60178
Phone: (815) 899-0339
Fax: (815) 899-2098
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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
Mailing address3498 Sanborn Ln, Dekalb, IL 60115-8304

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