Okla. Stat. tit. 36, § 2115

A. Each holder of one or more insurance policies or contracts issued by a domestic mutual insurer, other than a contract or reinsurance, is a member of the insurer with all the rights and obligations of such membership, and each such policy or contract so issued shall so specify. B. Any person, government or governmental agency, state or political estate, trustee or fiduciary may be a member of a domestic, foreign or alien mutual insurer. C. The insurer shall be entitled to charge and collect initial membership and/or policy fees, in addition to the premiums. Laws 1957, p. 307, § 2115.