California Code, Health and Safety Code - HSC § 11834.16

A license shall be valid for a period of two years from the date of issuance. The department may extend the licensure period for subsequent two-year periods upon submission by the licensee of a completed written application for extension and payment of the required licensing fee prior to the expiration date shown on the license. Failure to submit to the department the required written application for extension of the licensing period, or failure to submit to the department the required licensing fee prior to the expiration date on the license, shall result in the automatic expiration of the license at the end of the two-year licensing period.