The following definitions apply to this chapter:

(1) "Eligible participant" means a partner of a partnership or a shareholder of an S corporation that is a nonresident individual, a foreign C corporation, or a pass-through entity whose only Montana source income for the tax year is from partnerships or S corporations electing to file composite returns and pay composite taxes on their behalf.

(2) "Foreign C corporation" means a corporation that is not engaged in or doing business in the state. "Engaged in business" and "doing business" are defined in 15-31-101 , MCA, and ARM 42.23.102.

(3) A participant's "share of a partnership's or S corporation's income" is the aggregate of his, her, or its share of the pass-through entity's income, gain, loss, or deduction or item of income, gain, loss, or deduction.