Colorado Revised Statutes Title 24. Government State § 24-75-102. When appropriations expended--balance

(1)(a) Except as otherwise provided by law, including paragraph (b) of this subsection (1), all moneys appropriated by the general assembly may be expended or encumbered, if authorized by the controller, only in the fiscal year for which appropriated. Except as otherwise provided by law, any moneys unexpended or not encumbered from the appropriation to each department for any fiscal year shall revert to the general fund or, if made from a special fund, to such special fund. Determination of such expenditures or encumbrances shall be made no later than thirty-five days after the close of the fiscal year and pursuant to the provisions of section 24-30-202(11).