Got a 1099 nec late that I didn't know I was getting

Did you enter the self-employment income from that work --- you can enter the income even without a 1099NEC.   If you did not even enter the income, then you are going to need to amend.  But you have to wait until your return has been fully processed and wait for the Form 1040X to become available later in February.

If the IRS has accepted your return as filed then you must amend your tax return once the IRS has had a chance to process it as indicated by xmasbaby0. If your return is pending because the IRS has not yet begun accepting returns, you must wait to see if it is accepted or rejected.  If the return is rejected, this means it has not been filed, in which case you can update or change it before you resend it to the IRS.

You will be able to access and file an amended return on approximately February 23rd (Form 1040-X).  Use the link here to check to see when available:

• When will my forms be available for TurboTax Online or Desktop? 

Be sure to read all the instructions carefully, before you begin, so that TurboTax knows the original numbers and the changed numbers for your amendment.

• How to amend (change or correct) a return already filed?
• What is the deadline for filing an amended return?
• How to file an amended return with the IRS