N.D. Cent. Code § 54-52-17.10

Prior service retirees who are receiving benefits under this chapter on July 31, 2001, are entitled to receive an increase in benefits equal to six percent of the individual's present benefit, with the increased benefits payable beginning August 1, 2001. A prior service retiree is a former participating employee who receives a supplemental monthly payment from the retirement system based upon the original prior service credit system.