If your partnership reported excess business interest expense in Box 13, Code K of your 1065 Schedule K-1, you are required to file Form 8990.

Per Partner's Instructions for Schedule K-1 (Form 1065) Partner's Share of Income, Deductions, Credits, etc. (For Partner's Use Only), on page 12:

Code K. Excess business interest expense. If the partnership reports excess business interest expense to the partner, the partner is required to file Form 8990. See the Instructions for Form 8990 for additional information.

TaxAct now supports Form 8990 Limitation on Business Interest Expense Under Section 163(j).

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.