"Is it a selection I made during my input process?."
It appears to be a spurious error that can be corrected in Forms Mode (see below).
For a S corp (1120S), the fix is to answer Yes to Question 10 on Schedule B.
For a partnership/multi-member LLC (1065), the fix is to answer Yes to Question 24.
It’s not a spurious error. It’s triggered if you answered question 24 as ‘No’ in your partnership 1065 return (or I believe question 10 for 1120s returns, and that is what the previous answer refers to.
If you are filing your personal taxes, the 8990 is triggered by a K-1 you received from a partnership that has Code K on Line 13 (excess business interest) or Code AE on Line 20 (excess taxable income) or Code AF (excess taxable business interest income). There may be a trigger from C Corp K-1’s, but I’m not familiar with them, my return has all partnership K-1s.
This is a new form that TurboTax Deluxe, Premier, etc does not support. If you need it, you have fill out and print the Form 8990, attach it to your return, and file by mail.
Basically if the partnership that gave you the K-1 is subject to section 163(j) (they have gross receipts over $25 million, or have ownership in foreign companies) then the business may have had excess taxable income, excess taxable business interest income, or excess business interest expense that is passed on to you. The excess taxable income and excess taxable business interest income is just used to add to your own AGI to see if YOU are then subject to the 163(j) limits on business interest expense. We should all be so lucky to have that problem (gross receipts more than $25 million). But because you had a partnership that had excess taxable business interest expense, you have to fill out Form 8990 to see if their are in further limitations on your return.
You will probably only have one of the three items from any business entity in a given year. The excess business interest expense reduces your outside tax basis in the partnership this year, but the excess business interest expense is not deducted in the current year, but is carried over until next year, or indefinitely, until it can be offset by the then current year excess taxable income or excess business interest income FROM THE SAME entity. The excess taxable income and excess taxable interest income do not carry forward, but are used in your three year average of AGI plus those two excesses.