(a) Any moneys for a fund year in excess of the amount necessary to fund all obligations for that fund year may be declared to be refundable by the board of trustees not less than 12 months after the end of the fund year with the Commissioner's approval.
(b) Each member shall be given a written description of the refund plan at the time of application for membership. A refund for any fund year shall be paid only to those employers who remain participants in the group for the entire fund year. Payment of a refund based on a previous fund year shall not be contingent on continued membership in the group after that fund year.