Section 5150 is a section of the California Welfare and Institutions Code (specifically, the Lanterman-Petris-Short Act or "LPS") which allows a qualified officer or clinician to involuntarily confine a person deemed to have a mental disorder that makes them a danger to him or her self, and/or others and/or gravely disabled. A qualified officer, which includes any California peace officer, as well as any specifically designated county clinician, can request the confinement after signing a written declaration. When used as a term, 5150 (pronounced "fifty-one-fifty") can informally refer to the person being confined or to the declaration itself.