Hi, a 1099-MISC came in after I had completed my taxes that I had completely forgotten about. What do I need to do?

[AnnetteB6]

Since you have already filed your return, you will need to file an amended return to include the additional income reported on Form 1099-MISC.

Wait until your original return has been fully processed and you have received your refund (if expecting one), then complete and file the amended return.  If you have a balance due, then go ahead and amend your return before April 15th so that you will know the total amount that you need to pay by the due date to avoid penalties and interest.

See the instructions in the following TurboTax help article to get started:

How do I amend my federal tax return for this year?