Revisions to Welfare and Institutions Code limiting recommitment of mentally ill person to six months, and requiring additional criteria be found, does not apply to those initially committed prior to June 27, 2012. Rosalinda was committed to a locked facility as a mentally retarded person who posed a danger to herself or others (Welf. & Inst. Code, § 6500). Just prior to expiration of her one-year recommitment in 2012, the District Attorney petitioned to recommit her for another year. Rosalinda objected, claiming a recent amendment to Welfare and Institutions Code section 6500, which required additional criteria be found and provided for a maximum six-month recommitment, should be applied to her. The trial court ordered her committed for a year. She appealed. Held: Affirmed. Previously, the law provided for a one year involuntary commitment of a mentally retarded person who is a danger to herself or others. After the law was amended (June 27, 2012), it provided for a six-month commitment for mentally retarded persons who are found to be both dangerous and in “acute crisis.” The amendment applied prospectively. Persons first committed prior to the amendment’s effective date remain subject to a one-year commitment on a finding they are mentally retarded and dangerousness. This disparate treatment does not deny Rosalinda equal protection of the law because, although she is similarly situated to those committed on or after June 27, 2012, the Legislature had a rational basis for making the law prospectiveto find more cost-effective ways of isolating and treating developmentally disabled persons who pose a danger to themselves or others by implementing prospectively community-based treatment programs.