Notwithstanding any other provisions of this subpart to the contrary, the board shall offer coverage to the surviving spouse of any teacher who died prior to January 1, 1979, and to any teacher with eight or more years of creditable service who is not presently eligible to receive retirement benefits. The surviving spouse or teacher shall pay in monthly installments both the employer and employee premiums for such insurance coverage. The amount of the monthly premiums shall be equal to the rate of employer and employee contributions in effect during the existence of the coverage.