Okla. Stat. tit. 36 § 4018
If any statements, other than those relating to age, sex and identity are required as a condition to issuing an annuity or pure endowment contract, other than a reversionary, survivorship, or group annuity, and subject to Section 4020 of this article, there shall be a provision that the contract shall be incontestable after it has been in force during the lifetime of the person or of each of the persons as to whom such statements are required, for a period of two (2) years from its date of issue, except for nonpayment of stipulated payments to the insurer; and at the option of the insurer such contract may also except any provisions relative to benefits in the event of disability and any provisions which grant insurance specifically against death by accident or accidental means.
Okla. Stat. tit. 36, § 4018