N.C. Gen. Stat. § 54C-17
A State savings bank shall obtain and maintain insurance on all members' and customers' deposit accounts from an insurance corporation created by an act of Congress. Before the licensing of a savings bank, a certificate of incorporation duly recorded under G.S. 54C-14(c), is deemed to be sufficient certification to the insuring corporation that the savings bank is a legal corporate entity. The insurance shall be obtained within the time limit prescribed in G.S. 54C-19. Subject to the rules of the Commissioner of Banks, a State savings bank may obtain or participate in efforts to obtain insurance of deposits that is in excess of the amount eligible for federal insurance of accounts. This insurance is known as "excess insurance".
N.C. Gen. Stat. § 54C-17