15-30-3301. Definition of small business corporation. (1) Except as provided in subsection (2), the term "small business corporation" is synonymous with "S. corporation" as defined in 15-30-2101 and means a corporation for which a valid election under section 1362 of the Internal Revenue Code (26 U.S.C. 1362) is in effect.

(2) A corporation that would otherwise be a small business corporation may continue to be subject to the taxes imposed by Title 15, chapter 31, if all of the following conditions are met:

(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.