Ind. Code § 6-1.1-12-19

Sec. 19. (a) The deduction from assessed value provided by section 18 of this chapter (before its expiration) is first available in the year in which the increase in assessed value resulting from the rehabilitation occurs and shall continue for the following four (4) years. In the sixth (6th) year, the county auditor shall add the amount of the deduction to the assessed value of the real property. A reassessment under a county's reassessment plan prepared under IC 6-1.1-4-4.2 which occurs within the five (5) year period of the deduction does not affect the amount of the deduction.

(b) This section expires January 1, 2023.