Ohio Rev. Code § 145.431
Designation of a beneficiary for the purposes of section 145.40 of the Revised Code or a return of contributions to the beneficiary of a member participating in a PERS defined contribution plan shall be made under this section. A beneficiary shall be designated in writing duly executed on a form provided by the public employees retirement board and signed by the member. A designation under this section is not valid unless received by the board prior to the member's death.
A beneficiary designation made under this section applies to the PERS defined benefit plan or PERS defined contribution plan in which the member participated or, if the member participated in both the defined benefit plan and one or more defined contribution plans, to both the defined benefit plan and the defined contribution plans.
The last designation of any beneficiary revokes all previous designations. The member's marriage, divorce, marriage dissolution, legal separation, or withdrawal of account, or the birth of the member's child, or adoption of a child, shall constitute an automatic revocation of the member's previous designation.
R.C. § 145.431