N.D. Cent. Code § 26.1-13-18

The maximum amount of insurance which a county mutual insurance company may retain on a single risk other than under a liability insurance contract, after deduction of applicable reinsurance, may not exceed ten percent of the admitted assets of the company or thirty thousand dollars, whichever is the larger amount. The maximum amount of insurance which a county mutual insurance company may retain on a single risk under a liability insurance contract may not exceed one percent of the surplus maintained by the company.