Cal. Welf. & Inst. Code § 5908

On or before October 1, 1992, and in each following year, the counties contracting directly with the facility shall inform the facility of any intent to modify the quantity of services to be purchased in the subsequent fiscal year. Contracts for these services shall be completed by April 1 of each year for the following year. In the absence of cause, changes shall not be made without this notification.