Every health care service plan offering plan contracts to small employer groups shall in addition to complying with the provisions of this chapter and the rules adopted thereunder comply with the provisions of this article. At least 20 business days prior to renewing or amending a plan contract subject to this article which will be in force on the operative date of this article, a plan shall file a notice of material modification with the director. At least 20 business days prior to offering a plan contract subject to this article, all plans shall file a notice of material modification with the director. Any action by the director, as permitted under Section 1352, to disapprove, suspend or postpone the plan’s use of a plan contract shall be in writing, specifying the reasons that the plan contract does not comply with the requirements of this chapter.