(a) If the Secretary determines that an amendment to a State plan is essential during the effective period of the plan, the State shall make the amendment.
(b) A State shall also amend a State plan if there is a significant and relevant change in:
(1) The information or the assurances in the plan;
(2) The administration or operation of the plan; or
(3) The organization, policies, or operations of the State agency that received the grant, if the change materially affects the information or assurances in the plan.