Mont. Code Ann. § 20-9-351

If the money available for BASE aid is not the result of a reduction in spending under 17-7-140 and is not sufficient to provide the guaranteed tax base aid required under 20-9-366 through 20-9-369 and BASE aid support determined under 20-9-347, the superintendent of public instruction shall request the budget director to submit a request for a supplemental appropriation in the second year of the biennium that is sufficient to complete the funding of BASE aid for the elementary and high school districts for the current biennium.