Who Must File
If you are an individual, estate, or a trust, you must file Form N-158 to claim a deduction for your investment interest expense. Exception. You do not have to file Form N-158 if all of the following apply.
• Your investment income from interest and ordinary dividends is more than your investment interest expense.
• You do not have any other deductible investment expenses.
• You do not have any carryover of disallowed investment interest expense from 2020
Purpose of Form
Use Form N-158 to figure the amount of investment interest expense you can deduct for 2021 and the amount you can carry forward to future years. Your investment interest expense deduction is limited to your net investment income