Your answer is incorrect though. The partners tax basis is reduced this year by the amount of the K-1’s Line 13 Code K excess business interest income, but you don’t get the deduction this year, you get it in a future year when that same entity has enough excess taxable income or excess business interest income (Line 20, Code AE and AF respectively). But you need to file form 8990 to carry it forward. So it does have utility for the taxpayer, and is a required form if you have a Line 13 Code k entry.
