For taxable years beginning after December 31, 2019, a subtraction may be made of the amount of 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 due to the application of 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 of revenue that it qualifies as a Wisconsin qualified opportunity fund for the fund’s taxable year. A fund shall make the annual certifications under this subdivision no later than the due date, including extensions, of the fund’s corresponding income or franchise tax return under this chapter.