A person is permanently ineligible to have that person's name placed on the ballot at any election for the office of United States senator or representative in Congress if, by the start of the term for which the election is being held, that person will have served as a United States senator or a representative in Congress, or in any combination of those offices, for at least twelve years.
N.D. Cent. Code § 16.1-01-13
Term limits for United States senators and representatives in Congress
Official source: North Dakota Legislative Branch. Reproduced from public-domain North Dakota statutes; confirm against the official source for the current text. Not legal advice.