If you were a designated beneficiary of the IRA, you should already have received a Form 1099-R to report on your tax return.

If you instead received this money as a distribution from the decedents estate and are expecting to receive a Schedule K-1 (Form 1041) that is reportable on your 2017 tax return, you'll need to enter the Schedule K-1.  That's going to be difficult if you have not yet received the Schedule K-1.  However, IRA income passed through to you on a Schedule K-1 should appear in box 5 of the Schedule K-1 and propagate to Schedule E Part III.  If the actual Schedule K-1 ends up reporting a different amount than you reported on your filed tax return, you'll need to amend your filed tax return.