California Code, Government Code - GOV § 11520

(a) If the respondent either fails to file a notice of defense, or, as applicable, notice of participation, or to appear at the hearing, the agency may take action based upon the respondent's express admissions or upon other evidence and affidavits may be used as evidence without any notice to respondent; and where the burden of proof is on the respondent to establish that the respondent is entitled to the agency action sought, the agency may act without taking evidence.

(b) Notwithstanding the default of the respondent, the agency or the administrative law judge, before a proposed decision is issued, has discretion to grant a hearing on reasonable notice to the parties. If the agency and administrative law judge make conflicting orders under this subdivision, the agency's order takes precedence. The administrative law judge may order the respondent, or the respondent's attorney or other authorized representative, or both, to pay reasonable expenses, including attorney's fees, incurred by another party as a result of the respondent's failure to appear at the hearing.

(c) Within seven days after service on the respondent of a decision based on the respondent's default, the respondent may serve a written motion requesting that the decision be vacated and stating the grounds relied on. The agency in its discretion may vacate the decision and grant a hearing on a showing of good cause. As used in this subdivision, good cause includes, but is not limited to, any of the following: