What Is the Global Assessment of Functioning (GAF) Scale?

Medically Reviewed by Smitha Bhandari, MD on March 23, 2023

The Global Assessment of Functioning, or GAF, scale is used to rate how serious a mental illness may be. It measures how much a person's symptoms affect their day-to-day life on a scale of 0 to 100.

It's designed to help mental health providers understand how well the person can do everyday activities. The score can help figure out what level of care someone may need and how well certain treatments might work.

The GAF is based on a scale that was first used in 1962. It's been updated over time. In 2013, the manual that psychiatrists in the U.S. use to define and classify mental disorders dropped it in favor of a scale designed by the World Health Organization. But government agencies and insurance companies, as well as others, still use it and aren't expected to replace it any time soon.

A GAF rating can be based on many things, including:

  • An interview or questionnaire
  • Medical records
  • Information from the person's doctor, care givers, or close relatives
  • Police or court records about violent or illegal behavior

It's broken into 10 sections. These are known as anchor points. The higher your score, the better you're able to handle daily activities:

gaf chart


Show Sources


New York State Office of Mental Health: "Domains Of Assessment For Co-Occurring Disorders."

State University of New York at Albany, Counseling and Psychological Services.

Annals of General Psychiatry: "Guidelines for rating Global Assessment of Functioning."

Current Psychiatry Reviews: "Collecting Information for Rating Global Assessment of Functioning (GAF): Sources of Information and Methods for Information Collection."

Annals of General Psychiatry: "Global Assessment of Functioning: properties and frontier of current knowledge."

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders.

Journal of the American Academy of Psychiatry and the Law Online: "DSM-5 and the Assessment of Functioning: The World Health Organization Disability Assessment Schedule 2.0."

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