What's the oldest return I can file with TurboTax?

[eargus-ea-gmail-]

Can I file a return before 2018?

[xmasbaby0]

No.

TurboTax has software for 2019 onward.   Software is no longer available from TurboTax for earlier years, nor would it be supported even if you find it on eBay, etc.  Updates are not available.   It is also too late to receive a tax refund for a tax year earlier than 2019---those refunds have been forfeited.   BUT if you owe tax due you still have to pay with penalties and interest.   There might be other software providers that have software for those years, but you will not receive refunds for the returns even if the forms show a refund.

Online preparation and e-filing for 2019 and 2020 and 2021 is permanently closed.

To file a return for a prior tax year

 If you need to prepare a return for 2019, 2020 or 2021 you can purchase and download desktop software to do it, then print, sign,  and mail the return(s)

https://turbotax.intuit.com/personal-taxes/past-years-products/

You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.

Remember to prepare your state return as well—if you live in a state that has a state income tax.

https://ttlc.intuit.com/community/state-taxes/help/how-do-i-contact-my-state-department-of-revenue/0... 

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.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

Note:  The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac.  It cannot be used on a mobile device.

If you are getting a refund, there is not a penalty for filing past the deadline.  If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.

[xmasbaby0]

If you are so behind in filing tax returns that you need help, you should consider local paid help.  Do you even have your W-2's and/or 1099's to enter?   You may need to seek those from the employers, etc. who issued them. 

You might need to phone, drop in, email and/or snail mail an old employer to make sure they know where to send your W-2.

Every tax year has to be filed separately.  Do not try to combine them in any way--- do not even mail them in the same envelope.