Cal. Lab. Code § 4152

The statement, when filed, shall operate, within the meaning of Chapter 3 (commencing with Section 3600), to subject him or her to the compensation provisions thereof for the term of one year from the date of filing. Thereafter, without further act on his or her part, he or she shall be so subject for successive terms of one year each, unless at least 60 days prior to the expiration of such first or succeeding year, he or she files with the administrative director a notice that he or she withdraws his or her election.