N.C. Gen. Stat. § 116-144
Unless provided otherwise by law, the Board of Governors shall fix the tuition and required fees charged nonresidents of North Carolina who attend the institutions enumerated in G.S. 116-4 at rates higher than the rates charged residents of North Carolina and comparable to the rates charged nonresident students by comparable public institutions nationwide, except that a person who serves as a graduate teaching assistant or graduate research assistant or in a similar instructional or research assignment and is at the same time enrolled as a graduate student in the same institution may, in the discretion of the Board of Governors, be charged a lower rate fixed by the Board, provided the rate is not lower than the North Carolina resident rate.
N.C. Gen. Stat. § 116-144