For taxable years beginning after December 31, 2019, by subtracting from federal taxable income an amount equal to the gain excluded from federal gross income in the taxable year due to the application of 26 USC 1400Z-2 (b) (2) (B) (iii) for an investment held in a Wisconsin qualified opportunity fund for at least 5 years or 26 USC 1400Z-2 (b) (2) (B) (iv) for an investment held in a Wisconsin qualified opportunity fund for at least 7 years. In this subdivision, “Wisconsin qualified opportunity fund” has the meaning given in s. 71.05 (25m) (a) 2.

In the form and manner prescribed by the department, a fund shall annually certify to each investor and the department that it qualifies as a Wisconsin qualified opportunity fund for the fund’s taxable year. A fund shall make the annual certifications under this subd. 21. b. no later than the due date, including extensions, of the fund’s corresponding income or franchise tax return under this chapter.