The deadline for preparing or e-filing a 2018 return was on October 15, 2019. You cannot use online TurboTax to prepare your 2018 return. You can purchase desktop software and download it to a full PC or Mac. You will not be able to e-file; your return must be printed, signed and mailed.
https://turbotax.intuit.com/personal-taxes/past-years-products/
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
