N.D. Cent. Code § 54-52.6-14
The board shall allow distribution of the participating member's vested account balance if the board determines that the participating member has become totally and permanently disabled. If approved, the disabled member has the same distribution options as provided in subdivisions a and c of subsection 3 of section 54-52.6-13. However, if the member chooses the periodic distribution option, the member may only receive distributions for as long as the disability continues and the member submits the necessary documentation and undergoes medical testing required by the board, or for as long as the member participates in a rehabilitation program required by the board, or both. If the board determines that a member no longer meets the eligibility definition, the board shall discontinue the disability retirement benefit.
N.D.C.C. § 54-52.6-14