N.C. Gen. Stat. § 58-65-45
Whenever any hospital service corporation licensed under this Article and Article 66 of this Chapter makes a rate filing or any proposal to revise an existing rate schedule or contract form, the effect of which is to increase or decrease the charge for its contracts, or to set up a new rate schedule, and such rate schedule is subject to the approval of the Commissioner, such hospital service corporation shall file its proposed rate change or contract form and supporting data with the commissioner, who shall review the filing in accordance with the standards in G.S. 58-65-40. Such rate revision or new rate schedule with respect to individual subscriber contracts shall be guaranteed by the insurer, as to the contract and certificate holders thereby affected, for a period of not less than 12 months; or with respect to individual subscriber contracts as an alternative to giving such guarantee, such rate revision or new rate schedule may be made applicable to all individual contracts at one time if the corporation chooses to apply for such relief with respect to such contracts no more frequently than once in any 12-month period. Such rate revision or new rate schedule shall be applicable to all contracts of the same type; provided that no rate revision or new rate schedule may become effective for any contract holder unless the corporation has given written notice of the rate revision or new rate schedule not less than 30 days prior to the effective date of such revision or new rate schedule. The contract holder thereafter must pay the revised rate or new rate schedule in order to continue the contract in force. The Commissioner may promulgate reasonable rules, after notice and hearing, to require the submission of supporting data and such information as is deemed necessary to determine whether such rate revisions meet these standards. At any time within 60 days after the date of any filing under this section or G.S. 58-65-40, the Commissioner may give written notice to the corporation of a fixed time and place for a hearing on the filing, which time shall be no less than 20 days after notice is given. In the event no notice of hearing is issued within 60 days from the date of any filing, the filing shall be deemed to be approved, subject to modification by the Commissioner as authorized by G.S. 58-65-40. In the event the Commissioner gives notice of a hearing, the corporation making the filing shall, not less than 10 days before the time of the hearing, cause to be published in a daily newspaper or newspapers published in North Carolina, and in accordance with the rules and regulations of the Commissioner of Insurance, a notice, in the form and content approved by the Commissioner, setting forth the nature and effect of such proposal and the time and place of the public hearing to be held. If the Commissioner does not issue an order within 45 days after the day on which the hearing began, the filing shall be deemed to be approved, subject to modification by the Commissioner as authorized by G.S. 58-65-40.
N.C. Gen. Stat. § 58-65-45