TurboTax can only provide software for tax years 2018, 2019 and 2020. The older years are no longer available nor are they supported even if you can find them on eBay etc, you would not be able to update them. And....it is too late to receive tax refunds for any year earlier than 2018 The refunds have been forfeited even if the tax form shows a refund. BUT if you owe tax due it still has to be paid with penalties and interest.
You can seek local paid tax help, or you can get the paper forms to prepare by hand for the outdated years. Do you have all of your income information and documents like W-2's or 1099's? Any document showing tax withheld must be attached to the return when you mail it in.
Each tax year has to be filed separately using the forms for the specific tax year. They cannot be combined in any way--do not even put them in the same envelope when you mail them. Software for past years is available back to 2018. Any earlier years can only be prepared on paper forms by hand--and those refunds have been forfeited now.
Online preparation and e-filing for 2018 and 2019 and 2020 is permanently closed.
To file a return for a prior tax year
If you need to prepare a return for 2018, 2019 or 2020 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.
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.
Refunds for tax years 2017 or earlier have been forfeited and will not be paid to you even if shown on the tax return form. But if you owe tax due, you will still have to pay, and you will be billed later for the interest and penalties owed.
https://www.irs.gov/filing/where-to-file-paper-tax-returns-with-or-without-a-payment
2015
Form 1040 https://www.irs.gov/pub/irs-prior/f1040--2015.pdf
Form1040 Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2015.pdf
Form1040A https://www.irs.gov/pub/irs-prior/f1040a--2015.pdf
Form 1040A Instructions https://www.irs.gov/pub/irs-prior/i1040a--2015.pdf
Form 1040EZ https://www.irs.gov/pub/irs-prior/f1040ez--2015.pdf
Form 1040EZ Instructions https://www.irs.gov/pub/irs-prior/i1040ez--2015.pdf
2016
Form 1040 https://www.irs.gov/pub/irs-prior/f1040--2016.pdf
Form 1040 Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2016.pdf
Form 1040A https://www.irs.gov/pub/irs-pdf/f1040a.pdf
Form 1040AInstructions https://www.irs.gov/pub/irs-prior/i1040a--2016.pdf
Form1040EZ https://www.irs.gov/pub/irs-prior/f1040ez--2015.pdf
Form1040EZ Instructions https://www.irs.gov/pub/irs-pdf/i1040ez.pdf
2017
https://www.irs.gov/pub/irs-prior/i1040gi--2017.pdf
https://www.irs.gov/pub/irs-prior/f1040--2017.pdf
https://www.irs.gov/pub/irs-prior/f1040a--2017.pdf
https://www.irs.gov/pub/irs-prior/i1040a--2017.pdf
https://www.irs.gov/pub/irs-prior/f1040ez--2017.pdf
https://www.irs.gov/pub/irs-prior/i1040ez--2017.pdf