you need to either buy the desktop software for each year or get the forms from the IRS website and prepare your returns manually. online preparation for 2017 and 2018 is closed. even with the desktop software, you'll need to paper file the returns since e-filing them is closed. mail each year in a different envelope and if you are due a refund expect a wait that will exceed 4 months. use a method where you can track receipt. be sure to follow TT filing instructions including the need to attach any forms with withholding.
