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.
Notes / sourceSource: American Psychological Association [1/1/2007: modified definition]
About Taxonomy Code 103T00000X
The taxonomy code 103T00000X identifies Psychologist within the Behavioral Health & Social Service Providers provider grouping. It is a Level II — Classification code, which names a provider's occupation or service within the broader provider grouping.
NPI records show 74,525 registered providers whose primary or secondary taxonomy is this code. Of these, 14,440 (19%) are registered as organizations and 60,085 (81%) as individual providers. The states with the most psychologist providers are California (10,214), New York (6,402), Michigan (3,964). For Medicare enrollment, it crosswalks to specialty code 62 (Psychologist).
Taxonomy codes are self-selected by the provider based on their education and training; they describe the provider's type and specialty, not the specific services rendered.
Provider Composition & Statistics
74,525Total providers
14,440Organizations 19%
60,085Individuals 81%
41,825Female
18,147Male
113Undisclosed
19% Organizations81% Individuals
Among individual providers:
70% F30% M
Gender is recorded for individual providers only; organizations are not gendered. Source: NPPES, last updated 2026-07-26T00:00:00.