Hopefully you didn't use the current online product to file your 2018 tax return. It can only be used to file a 2019 return. If you used it to file 2018 and efiled it, the IRS may reject it. If they don't and it is accepted, you will now have to prepare, print and mail an amended return form 1040X to delete all your 2018 information and enter your 2019 information and then mail it to the IRS.
DO NOT change your original tax return until you start the amended return. If you have already changed it from the way it was originally filed and accepted, you must change it back before you start the amended return. Here is an FAQ to help you:
https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed
An amended return cannot be efiled. You must print and mail it yourself. TurboTax does not print and mail it for you. Use the filing instructions that print with your amended return for what to include and where to mail ti. In normal times, it takes the IRS about 16 weeks to process an amended return. It is taking much longer now.
To prepare and file a 2018 tax return, you must buy, download and install the 2018 product on your computer. See this: https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2018 return can no longer be efiled. You must print and mail it yourself. TurboTax does not print an mail it for you. Use the filing instructions that print with your return to know what to include and where to mail it.
