Natural persons.
Except as provided in sub. (6) (b): 1.
(1)#
Every individual domiciled in this state during the entire taxable year who has a gross income at or above a threshold amount which shall be determined annually by the department of revenue. The threshold amounts shall be determined for categories of individuals based on filing status and age, and shall include categories for single individuals; individuals who file as a head of household; married couples who file jointly; and married persons who file separately. The department of revenue shall establish a threshold amount for each category of individual at an amount at which no individual in that category whose gross income is below that amount has a state income tax liability.
(2)#
Every nonresident person and every person who changes domicile into or out of this state during the taxable year shall file a return if the person is unmarried and has gross income of $2,000 or more, or if the person is married and the combined gross income of the person and his or her spouse is $2,000 or more, except that a return is not required to be filed if all the income is exempt from income tax under s. 71.05 (1) (g).
(5)#
For taxable years beginning on or after January 1, 1994, every natural person for whom the taxpayer is entitled to an exemption for the taxable year under section 151 (c) of the Internal Revenue Code shall file a return if that natural person has any amount of unearned income and that person has gross income of at least $500 adjusted for inflation in the manner prescribed by sections 1 (f) (3) to (6) and 63 (c) (4) of the Internal Revenue Code. The department of revenue shall incorporate the changes in the income tax forms and instructions.