N.C. Gen. Stat. § 120-4.28
The designated beneficiary of a member who dies in service before retirement but after age 60 and after completing five years of creditable service or after completing 12 years of creditable service is entitled to Option 2 prescribed by G.S. 120-4.26.
In the event that a retirement allowance becomes payable to the principal beneficiary designated to receive a return of accumulated contributions pursuant to this subsection and that beneficiary dies before the total of the retirement allowances paid equals the amount of those accumulated contributions over the total of the retirement allowances paid to the beneficiary, the allowance shall be paid in a lump sum to the person or persons the member has designated as the contingent beneficiary for return of accumulated contributions, if the person or persons are living at the time the payment falls due, otherwise to the principal beneficiary's legal representative. In the event that a retirement allowance becomes payable to the contingent beneficiary designated to receive a return of accumulated contributions pursuant to subsection (m) of this section and that beneficiary dies before the total of the retirement allowances paid equals the amount of the accumulated contributions of the member at the date of the member's death, the excess of those accumulated contributions over the total of the retirement allowances paid to the beneficiary shall be paid in a lump sum to the contingent beneficiary's legal representative.
N.C. Gen. Stat. § 120-4.28