N.D. Cent. Code § 28-20-34
Interest is payable on judgments entered in the courts of this state at the same rate as is provided in the original instrument upon which the action resulting in the judgment is based, which rate may not exceed the maximum rate provided in section 47-14-09. If such original instrument contains no provision as to an interest rate, or if the action resulting in the judgment was not based upon an instrument, interest is payable at the rate of twelve percent per annum through December 31, 2005. Beginning January 1, 2006, the interest is payable at a rate equal to the prime rate published in the Wall Street Journal on the first Monday in December of each year plus three percentage points rounded up to the next one-half percentage point and may not be compounded in any manner or form. On or before the twentieth day of December each year, the state court administrator shall determine the rate and shall transmit notice of that rate to all clerks of court and to the state bar association of North Dakota. As established, the rate shall be in effect beginning the first day of the following January through the last day of December in each year. Except as otherwise provided in this section, interest on all judgments entered in the courts of this state before January 1, 2006, must remain at the rate per annum which was legally prescribed at the time the judgments were entered, and such interest may not be compounded in any manner or form. Interest on unpaid child support obligations must be calculated under section 14-09-25 according to the rate currently in effect under this section regardless of the date the obligations first became due and unpaid.
N.D.C.C. § 28-20-34