Okla. Stat. tit. 74, § 1318

No former employee who is reemployed by a participating entity within twenty-four (24) months after the date of termination of previous employment shall be enrolled in the Oklahoma Employees Insurance and Benefits Plan authorized by Sections 1301 through 1329.1 of this title, for a greater amount of life insurance or life benefit than the amount for which the life of the former employee was insured under the plan at the date of termination of employment, except upon the former employee furnishing evidence of insurability, satisfactory to the Oklahoma Health Care Authority, and any greater amount of benefit or insurance provided the employee shall be at the former employee’s cost.