Allowing an individual to claim a credit against the State income tax for certain allowable union dues paid by the individual during the taxable year if the union dues would have been allowed as a deduction under the Internal Revenue Code for a taxable year beginning after December 31, 2016, but before January 1, 2018; providing for the calculation of the credit; making the credit refundable; defining "allowable union dues"; applying the Act to taxable years beginning after December 31, 2018, but before January 1, 2026; etc.