W. Va. Code § 5-16-25

The finance board shall establish and maintain a reserve fund for the purposes of offsetting unanticipated claim losses in any fiscal year. The finance board shall maintain the actuarily recommended reserve in an amount no less than 10 percent of the projected total plan costs for that fiscal year in the reserve fund, which is to be certified by the actuary and included in the final, approved financial plan submitted to the Governor and Legislature.