The federal Tax Cuts and Jobs Act amended Internal Revenue Code Section 163(j) to limit the business interest expense deduction. For tax years beginning after December 31, 2017, and before January 1, 2020, Tennessee recognized this federal limitation. However, for tax years beginning on or after January 1, 2020, Tennessee decoupled from the TCJA amendment of Section 163(j) and the business interest expense deduction is no longer limited. Read more here.