N.D. Cent. Code § 54-52-02
All departments, boards, institutions, commissions, or agencies of the state of North Dakota, the Garrison Diversion Conservancy District, district health units, the supreme court, and the district courts, hereinafter referred to as agency, shall participate in a retirement system which will provide for the payment of benefits to state and political subdivision employees or to their beneficiaries thereby enabling the employees to care for themselves and their dependents and which by its provisions will improve state and political subdivision employment, reduce excessive personnel turnover, and offer career employment to high-grade men and women. However, a city health department providing health services in a city-county health district formed under chapter 23-35 is not required to participate in the public employees retirement system but may participate in the public employees retirement system under section 54-52-02.1. Employees presently covered by a pension plan or retirement plan to which the state is contributing, except social security, are not eligible for duplicate coverage except as provided under sections 39-03.1-14.1 and 54-52-17.2.
N.D.C.C. § 54-52-02