BenefitsRUs21, I agree with CuseFan, but would add that it, e.g., this is a corporation and you have a board resolution adopted (e.g., by unanimous consent or at a meeting of directors) before end of 2018, that may be enough for adoption. Depending on the entity's type and governance, adoption may occur before signature by officer on amendment. often, however, signature is all you have, so the foregoing may not be relevant to your situation.