So--you already filed a tax return with a W-2 on it? You cannot file again. All of your income is required to be on the SAME tax return. So you will need to amend the tax return you already filed to add your 1099Misc to that return.
When the first tax return has been fully processed you can amend. Do not amend sooner or you could just confuse the IRS and delay processing for months.
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ALL of your W-2’s and/or 1099’s were supposed to be on the same tax return. Remember that next year and do not e-file until you have everything. Now you have to prepare an amended return to add that 1099Misc.
https://ttlc.intuit.com/questions/2566895-what-does-it-mean-to-amend-a-return
How do I amend my 2019 TurboTax Online return?
A 1040X cannot be e-filed. It must be printed and mailed. It will take about 4 months for the IRS to process an amended return. It is a good idea to use a mailing service that will track it, like UPS or certified mail, so you will know it was received.
Wait about 3 weeks from mailing and you can check the status of your amended return:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
https://ttlc.intuit.com/questions/1908543-do-i-need-to-amend