In administering the medical assistance programs established under this chapter, the division shall formulate such methods, policies, procedures, standards and criteria, except medical standards and criteria, as may be necessary for the proper and efficient operation of those programs in a manner consistent with simplicity of administration and the best interests of recipients. [unchanged text not shown] The division may adopt, promulgate, amend and rescind rules and regulations suitable or necessary to carry out the provisions of this chapter and said Title XIX and any amendments thereto, and as interpreted from time to time by the Secretary. Rules and regulations which restrict eligibility or covered services require a public hearing under section 2 of chapter 30A. [unchanged text not shown]