Montana Title 15. Taxation § 15-30-3301. Definition of small business corporation

(a) on December 31, 1991, the corporation was doing business in Montana and had a valid subchapter S. corporation election but had not elected to be taxed as a Montana small business corporation;

(b) after December 31, 1991, the corporation has not filed as a Montana small business corporation; and

(c) the corporation files a corporate income tax return, as required by 15-31-111, reporting all income or loss as determined under Title 15, chapter 31, and attaches a copy of the federal subchapter S. corporate tax return.