C.R.S. § 39-22-321

For the purposes of this subpart 2, unless the context otherwise requires: (1) “Income attributable to the state” means items of income, loss, deduction, or credit of the S corporation apportioned or allocated to this state pursuant to section 39-22-303.5 , 39-22-303.6 , or 39-22-303.7 . (2) “Income not attributable to the state” means all items of income, loss, deduction, or credit of the S corporation other than income attributable to the state. (3) “Post-termination transition period” means that period defined in section 1377 (b)(1) of the internal revenue code. (4) “Pro rata share” means the portion of any item attributable to an S corporation shareholder for a taxable period determined in the manner provided in, and subject to any election made under, section 1377 (a) or 1362 (e), as the case may be, of the internal revenue code. (5) “Taxable period” means any taxable year or portion of a taxable year during which a corporation is an S corporation.