Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 30 days.

DR. GREGORY HARRY POWELL PHD
NPI 1598737629
Psychologist in Frederick, MD

Active since February 02, 2006
97 THOMAS JOHNSON DR, STE 202, FREDERICK, MD 21702(301) 695-6455(301) 695-6456 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Jul 13, 2026, Sep 6, 2023, Jul 21, 2022 (3 updates tracked since 2022).

About Dr. Gregory Harry Powell Phd NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. GREGORY HARRY POWELL PHD (NPI 1598737629) is an individual psychologist in Frederick, Maryland, licensed in Maryland (2236) and active in the NPI registry since February 2006.

NPPES Registry Identity

NPI1598737629
Entity TypeIndividualMale
Primary Taxonomy103T00000X
Provider Legal NameDR. GREGORY HARRY POWELLCredential: PHD
Location Address97 THOMAS JOHNSON DR, STE 202Frederick, MD 21702
Mailing Address97 Thomas Johnson Dr, Ste 202Frederick, MD 21702 · (301) 695-6455 · Fax (301) 695-6456
Fax(301) 695-6456
Sole ProprietorNo
Enumeration DateFebruary 2, 2006
Last NPPES UpdateJuly 13, 20263 updates tracked since enumeration
NPI 1598737629 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

Primary SpecialtyPsychologistBehavioral Health & Social Service Providers
Taxonomy Code103T00000X
License Licensed in MD · 2236
Definition
A psychologist is an individual who is licensed to practice psychology which is defined as the observation, description, evaluation, interpretation, and modification of human behavior by the application of psychological principles, methods, and procedures, for the purpose of preventing or eliminating symptomatic, maladaptive, or undesired behavior and of enhancing interpersonal relationships, work and life adjustment, personal effectiveness, behavioral health, and mental health. The practice of psychology includes, but is not limited to, psychological testing and the evaluation or assessment of personal characteristics, such as intelligence, personality, abilities, interests, aptitudes, and neuropsychological functioning; counseling, psychoanalysis, psychotherapy, hypnosis, biofeedback, and behavior analysis and therapy; diagnosis and treatment of mental and emotional disorder or disability, alcoholism and substance abuse, disorders of habit or conduct, as well as of the psychological aspects of physical illness, accident, injury, or disability; and psycheducational evaluation, therapy, remediation, and consultation. Psychological services may be rendered to individuals, families, groups and the public.
97 THOMAS JOHNSON DR, Frederick, MD 21702

Other Providers at the Same Location NPPES 12

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

Psychiatry & Neurology (Forensic Psychiatry)
97 THOMAS JOHNSON DR, SUITE 102
FREDERICK, MD 21702
Obstetrics & Gynecology
97 THOMAS JOHNSON DR, SUITE 101
FREDERICK, MD 21702
Psychologist
97 THOMAS JOHNSON DR, SUITE 202
FREDERICK, MD 21702
Psychologist
97 THOMAS JOHNSON DR, STE 202
FREDERICK, MD 21702
Internal Medicine (Cardiovascular Disease)
97 THOMAS JOHNSON DR, STE 100
FREDERICK, MD 21702
Psychologist
97 THOMAS JOHNSON DR, SUITE 202
FREDERICK, MD 21702
Obstetrics & Gynecology
97 THOMAS JOHNSON DR, SUITE 101
FREDERICK, MD 21702
Pediatrics (Pediatric Cardiology)
97 THOMAS JOHNSON DR
FREDERICK, MD 21702

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Gregory Powell's NPI number?

The NPI number for Gregory Powell is 1598737629. It was assigned to this individual provider in the NPPES registry on February 2, 2006.

Where is Gregory Powell located?

Gregory Powell practices at 97 Thomas Johnson Dr Ste 202, Frederick, MD 21702. The listed phone number is (301) 695-6455.

What is Gregory Powell's specialty?

The primary specialty registered for this NPI is Psychologist with taxonomy code 103T00000X.

When was this NPI record last updated?

The NPPES record for Gregory Powell was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 23 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.