The TurboTax Full Service option is only available using the TurboTax online editions for tax year 2023.
Prior year tax returns can only be completed using the TurboTax desktop editions installed on a personal computer, Windows or Mac.
To complete and file a prior year (2022 thru 2020) tax return using TurboTax you would need to purchase, download and install on a personal computer one of the desktop editions for each tax year required from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A prior year tax return can only be printed and mailed, it cannot be e-filed using TurboTax.
When mailing multiple tax years you need to use a separate envelope for each year. You should also use a tracking service from the US post office so that you will have proof the tax returns were received by the IRS.
NOTE - The 2020 tax return that includes a tax refund Must be mailed on or before April 15. 2024. If mailed after that date the tax refund will not be paid.
