Mont. Code § 15-31-522
If the department determines that the assessment or collection of the tax or a deficiency in tax due under any corporate income tax statute of Montana for any taxable period will be jeopardized in whole or in part by delay, it may mail notice of its findings to the taxpayer, together with a demand for immediate payment of the tax or deficiency declared to be in jeopardy, including penalty and accrued interest. In the case of a tax for a current period, the department may declare the taxable period of the taxpayer immediately terminated and shall mail or issue notice of its findings to the taxpayer, together with a demand for immediate payment of the tax based on the period declared terminated. A jeopardy assessment is immediately due and payable, and proceedings for collection may be commenced at once.
§ 15-31-522, MCA