If the credit allowed under this chapter in any taxable year exceeds the total of tax otherwise payable by the employer for that taxable year, the employer may apply the excess as a credit for succeeding taxable years until the earlier of:
A. The full amount of the excess is used; or
B. The expiration of the fifth taxable year after the taxable year in which the costs to provide long-term care insurance as part of an employee benefit package were incurred.