(1) “Flow-through entity” means an S corporation, partnership, limited partnership, limited liability partnership, or limited liability company. Flow-through entity does not include a publicly traded partnership as that term is defined in section 7704 of the internal revenue code that has equity securities registered with the securities and exchange commission under section 12 of title I of the securities exchange act of 1934, 15 USC 78l.

  (2) “Gross income” means gross income as defined in the internal revenue code.

  (3) “Internal revenue code” means the United States internal revenue code of 1986 in effect on January 1, 2018 or at the option of the taxpayer, in effect for the tax year.

  (4) “Member of a flow-through entity” means a shareholder of an S corporation; a partner in a partnership or limited partnership; or a member of a limited liability company.

  (5) “Nonresident member” means any of the following that is a member of a flow-through entity:

  (a) An individual who is not domiciled in this state.

  (b) A nonresident estate or trust.

  (c) A flow-through entity with a nonresident member.