A PHP, or partial hospitalization program, is a type of day treatment program used to treat mental illness and substance abuse. It is a structured, intensive outpatient treatment program that typically takes place five days a week for four hours a day. Patients continue to reside at home but commute to a treatment center up to seven days a week. PHP treatment is considered an intensive level of treatment due to the requirement of 20 hours per week of therapy along with medication management. It is more intensive than traditional individual therapy, which is typically a once-weekly session for 50 minutes, but less intensive than an inpatient hospitalization or a residential treatment center.

PHPs are most often used to treat mental health conditions such as depression, post-traumatic stress disorder, substance abuse, or something else. They are also used to handle acutely ill persons who are able to better understand their illness, become adjusted to medication regimes, develop important coping skills, and set recovery goals that enable them to function effectively as recovered individuals in society. PHPs are recommended for those with serious mental health conditions who need a higher level of care and whose symptoms may not be managed or improve enough from weekly outpatient therapy sessions or meetings with a psychiatrist.

PHP treatment is a personalized experience that is designed to meet the specific strengths, needs, and treatment goals of each participant. Depending on the needs of each participant, their time in PHP may include group therapy, individual therapy, medication management, and some level of family work. Group therapy is one of the foundational elements of PHP treatment, and partial hospitalization programs for mental health typically offer multiple group therapy sessions each day. Individual therapy is also included in PHP treatment.