Ins. Code, § 4097.15

(a) Notwithstanding any other provision of law and except as otherwise provided in subdivision (b), actions concerning any plan of conversion, proposed plan of conversion, plan amendment, or proposed plan amendment under this article or any acts taken or proposed to be taken under this article shall be commenced within one year after the plan of conversion or plan amendment is filed in the office of the commissioner pursuant to subdivision (d) of Section 4097.02 or subdivision (a) of Section 4098.1, or six months from the effective date of the plan of conversion, whichever is later. If the plan of conversion is withdrawn, the actions or acts shall be commenced within six months from the date the board of directors approves a resolution to withdraw the plan. If an action concerns or arises out of a plan amendment or proposed plan amendment made under Section 4097.18, the applicable time period is measured from the filing, effective date, or approval of withdrawal of the plan amendment, whichever is later.

(b) Judicial review of any act of the commissioner or any other governmental body or officer concerning or arising out of any plan of conversion, proposed plan of conversion, plan amendment, or proposed plan amendment under this article may only be had by filing a petition for a writ of mandate within 30 days of the date of the act. However, any petition seeking judicial review shall be filed no later than 30 days from the effective date of the plan of conversion or plan amendment, whichever is the subject of the petition.