Ohio Revised Code Title LVIII. Trusts § 5815.27

(A) A provision in a will or trust agreement, which provision pertains to the payment of any taxes that are imposed by reason of the testator's or trust creator's death, does not include the payment of any portion of any tax that is imposed on any transfer under any other will or trust agreement by Chapter 13 of subtitle B of the “Internal Revenue Code of 1986,” 100 Stat. 2718, 26 U.S.C. 2601-2624, as amended, unless the provision of the will or trust agreement specifically states, using the words “generation-skipping transfer tax,” that the payment of the tax imposed under that chapter is included within the provision of the will or trust agreement.

(B) This section applies to wills and trust agreements that are executed before or after March 14, 1979.