The important issue is the year for the 1099-MISC.
If this is a 2017 Form 1099-MISC, file it with your 2017 tax return.
If this is a 2016 Form 1099-MISC, you may just want to wait until the IRS sends you a notice.
If you don't report a 2016 (or 2017) 1099-MISC,
the IRS may send you a Notice of
Proposed Tax Increase later this year - it will depend on the amount of the payment. The same process is usually
followed by states.
It
isn't an audit, but a
proposed bill for the tax on that 1099-MISC income, plus any interest or
penalties. They do all the calculations and provide a payment voucher if you
agree to the change. You don't need to amend your return, you would just have
to pay the proposed increase in tax.
(If the 1099-MISC was an expense reimbursement, see: 1099-MISC for Expense
Reimbursement)
