PSD's can fly, but need to fill out paperwork in advance
Yes, Psychiatric Service Dogs (PSDs) can fly in the cabin without pet fees but only if they meet specific requirements. Airlines require passengers to complete a Department of Transportation (DOT) PSD form before flying. The dog must be trained to perform tasks related to a diagnosed disability and behave well in public settings.
Be sure to submit your paperwork in advance and check with your airline for any additional requirements.