5150 (Involuntary psychiatric hold)
Section 5150 is a section of California's 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 a danger to himself, herself, 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 can informally refer to the person being confined or to the declaration itself.

# The process
Confinement under section 5150 lasts for up to 72 hours from the time the declaration is written. WIC 5151 requires an assessment prior to admission to the facility  in order .. to determine the appropriateness of the involuntary detention. During the period of confinement, a confined individual is evaluated by a mental health professional to determine if a psychiatric admission is warranted. Confinement and evaluation usually occurs in a county mental health hospital or in a designated Emergency Department. If the individual is then admitted to a psychiatric unit, only a psychiatrist may rescind the 5150 and allow the client to either remain voluntarily or be discharged.
On or previous to the expiration of the 72 hours, the psychiatrist must assess the client to see if they still meet criteria for hospitalization. If so, the client may be offered a voluntary admission.  If it is refused, then another hold, the 5250, must be written to continue the involuntary confinement of the client. If the 72 hour timeframe has elapsed before the client is offered a voluntary admission or placed on the 5250, the client must be immediately released.
A 5150 written by a peace officer is valid in any county in California; therefore, a client could theoretically be moved from one county to another according to available resources. When the 5150 is written by a designated clinician, the hold is only valid in that county. The designated clinician is only able to write a 5150 while present at the facility where they work, unless they work as part of a Psychiatric mobile response team.

## Contesting the hold
The patient under a 5150 hold has a limited ability to contest the legality of the hold. While the patient has the right of demanding a writ of habeas corpus, it is up to the county public defender whether to file it or not. Since such a writ may take a day or two to file, the public defender usually chooses not to pursue it as the patient's hold would expire before the anticipated court date.

# 5150 criteria
The criteria for writing requires probable cause. This includes danger to self, danger to others together with some indication, prior to the administering of the hold, of symptoms of a mental disorder, and/or grave disabilityas noted below. The conditions must exist under the context of a mental illness and the person must be refusing psychiatric treatment.
- Danger to self: The person must be an immediate threat to themselves, usually by being suicidal. Someone who is severely depressed and wishes to die would fall under this category.
- Danger to others: The person must be an immediate threat to someone else. A person hearing voices telling whom to kill someone would fall under this category.
- Gravely disabled:
Adult (patients over 18 years of age): The person is unable to provide for his/her food, clothing, and/or shelter, and there is no indication that anyone is willing or able to assist him/her in procuring these needs. This does not necessarily mean homeless, as a homeless person who is able to seek housing (even in a temporary shelter) when weather demands it would not fall under this category.
Minor (patients under 18 years of age): The person is unable to provide for his/her food, clothing, and/or sheltereven if these are supplied directly.
- Adult (patients over 18 years of age): The person is unable to provide for his/her food, clothing, and/or shelter, and there is no indication that anyone is willing or able to assist him/her in procuring these needs. This does not necessarily mean homeless, as a homeless person who is able to seek housing (even in a temporary shelter) when weather demands it would not fall under this category.
- Minor (patients under 18 years of age): The person is unable to provide for his/her food, clothing, and/or sheltereven if these are supplied directly.
- Mental disorder: Undefined by statute or regulation.  Page 14 of the LA County LPS Designation Manual states that the initiator must be able to articulate behavioral symptoms of a mental disorder either temporary or prolonged (People v. Triplett,(1983) 144 Cal. App. 3d 283).

# Required documentation
There are two legal documents, the 5150 application itself and the patient advisement form (5157(c)). The LA County LPS Designation Manual stipulates that, prior to the completion of the 5150 application, the initiator must conduct and document a face-to-face interview with the patient. On the 5150 application, the initiator is required to ..give sufficiently detailed information to support the belief that the person for whom the is in fact a danger to others, a danger to himself/herself and/or gravely disabled. The 5150 Application contains the words ...as a result of a mental disorder.. but does not stipulate documentation  of evidence of ..behavioral symptoms of a mental disorder....., defined in  People v. Triplett (1983)  as a necessary part of probable cause. The 5150 Application requests no explicit documentation of the required face-to-face interview.

# Patient rights while under section 5150
Patients admitted under section 5150 retain all rights under the Lanterman-Petris-Short Act. With the exception of being able to freely leave the facility they are placed in, patients have all rights accorded to a voluntarily admitted client. This includes the rights to:
- humane care
- religious freedom and practice
- participate in publicly supported education
- be free from abuse or neglect
- refuse medications except in emergency situations where danger to life is present; or by court order where the patient is found to lack the capacity to give or refuse informed consent via either a Riese hearing or via conservatorship.
- wear their own clothes
- visitors
- writing materials (including sending mail though they may be charged for postage)
- safe storage and access to their personal property
- have access to private phone conversations (though may be responsible for toll charges)
- speak with a Patient's Rights Advocate
- go outside for exercise and leisure (usually in a fenced area)
- access their money in amounts for small purchases (vending machine, etc.)
- be free from discrimination
- refuse their picture taken for ID

## Good cause
Denying any of the patient's rights requires good cause. Good cause being defined as the belief of the professional in charge of care for the client that the specific right would cause
- a danger to self or others;
- a serious infringement on the rights of others; or
- serious damage to the facility;
and that there is no less restrictive measure that would protect against those occurrences.
Patient rights can not be denied as a condition of admission nor as part of a treatment plan such as being labeled a privilege or as punishment. Any time a right is denied under good cause it must be documented in the patient's medical record and explained to the patient. The denial must be reviewed regularly and must be removed once good cause no longer exists.

# Popular culture references
- Because this section is a provision of California law, and because so many television programs and movies are made in and around Los Angeles, the term "5150" is not uncommonly heard on television and in movies, principally spoken by police officers or medical workers.
- The inside cover of Van Halen's 1986 album 5150 includes a photo where all the band members are in straitjackets. Eddie Van Halen would also name his home recording studio and a series of guitar amplifiers made by Peavey Electronics after this code.
- 5150 is also the name of Eazy E's album 5150: home 4 tha sick, with the tagline "Considered armed, dangerous & temporarily insane".
- TNA Wrestling faction LAX have 5150 on their shirts, and explained the meaning to the fans during an iMPACT! show.
- Ice Cube's song "Steal the Show", from the album Laugh Now, Cry Later, features the lyric "I just hope you ain't 5150, that's a crazy ho even though she pretty."
- D12's song "Good Die Young", from the album D12 World, features the lyric "I got married, my wife name is DPeace to 31 and 51-50..."
- John Lee Hooker Junior's song "Cold As Ice" (from the album of the same name) laments:  "I've been diagnosed as a 5150... I got mental disorder, that's a direct result of messing with that woman."
- 5150 is used for fiftyonefifty clothing company 
- 5150 is the name of a song from The Definitive Act (album), by Tsunami Bomb
- 5150 is the name of a miniatures wargame, published by Two Hour Wargames
- 5150 is the name of a wrestling move use by "Citizen" X
- 5150 has also been seen in personal ads on some dating web sites, usually something like "not looking for anyone who could be deemed as 5150".
- A patient who was a 5150 was featured in the first season's second episode of the ABC Series Private Practice.