Indiana Code Title 6. Taxation § 6-8.1-1-8

Sec. 8. (a) This chapter and IC 6-8.1-2 through IC 6-8.1-10-1 (except IC 6-8.1-5-2) apply after December 31, 1980, regardless of when the tax liability arose.  If the tax liability was assessed before January 1, 1981, the rights and duties of the taxpayer and the state are determined (except for interest on the liability for which IC 6-8.1-10-1 applies beginning January 1, 1981) with regard to the assessment, hearing, and appeals procedures and limitations that existed at the time of the tax liability assessment and before January 1, 1981, notwithstanding the repeal of those procedures and limitations.

(b) Except as provided in subsection (c), IC 6-8.1-5-2 and IC 6-8.1-10-2.1 through IC 6-8.1-10-7 apply only with respect to taxes imposed for periods ending after December 31, 1980.  Tax liabilities arising before January 1, 1981, are, with respect to additions to tax and penalties, determined, administered, and assessed under the appropriate listed tax laws in effect on December 31, 1980, instead of under this article.  The rights and duties of the taxpayers and the state under those laws are fully and completely preserved with respect to the additions to tax and penalties.

(c) IC 6-8.1-10-2.1 through IC 6-8.1-10-7 may apply to tax liabilities arising during any period that ends before January 1, 1981, if: