The purpose of this article is to use the guidelines of the Lanterman-Petris-Short Act to explain the legal concepts involved in evaluating a mentally ill person for involuntary psychiatric admission to hospital & to examine other relevant civil commitment considerations. The Lanterman-Petris-Short Act was written with the following goals: to end indeterminate commitments, to ensure prompt evaluation of civilly committed persons, to enhance public safety & to safeguard the civil rights of the mentally ill. This legislation was first introduced in 1967 & implemented in 1969. (LC) (4 refs)