California Code, Insurance Code - INS § 11535

(a) A domestic incorporated mutual life insurer, or life and disability insurer, issuing nonassessable policies on a reserve basis may be converted into an incorporated stock life or stock life and disability insurer issuing, on a reserve basis, nonassessable policies of life insurance or of both life and disability insurance. To that end, it may provide and carry out a plan for the conversion by complying with the requirements of this chapter.

(b) A domestic incorporated mutual insurer not referred to in subdivision (a) and that is not a medical malpractice mutual insurer as defined in subdivision (i) of Section 4097.01, which may be referred to in this chapter as a mutual property-casualty insurer, may be converted into an incorporated stock property-casualty insurer. To that end, it may provide and carry out a plan for the conversion by complying with the requirements of this chapter.A medical malpractice mutual insurer as defined in subdivision (i) of Section 4097.01 may not convert to a stock insurer under this chapter.

(c) A mutual holding company may be converted into a stock corporation. To that end, it may provide and carry out a plan for the conversion by complying with the requirements of this chapter.

(d) As part of the conversion authorized in this section, a domestic incorporated mutual insurer may merge with an incorporated stock insurer, if the merging insurers comply with the provisions of this code applicable to their participation in the merger, or may transfer its domicile to any other state, if the insurer complies with Section 709.5.