; application of amendments (a) Effective date Except as provided in subsection (b), this Act and the amendments made by this Act shall take effect 180 days after the date of the enactment of this Act. (b) Application of amendments The amendments made by this Act shall not apply with respect to certification periods that begin before the effective date of this Act. The Secretary of Agriculture shall provide States with not less than a 180-day hold harmless period after the date on which the Secretary issues guidance to implement the amendments made by this Act.