TurboTax is *NOT* an e-file product. It is a do-it-yourself tax preparation product. It just "happens" to include the ability to e-file, until the IRS closes e-filing for a tax year.
The IRS (not TurboTax or anyone else) determines when e-filing closes for a tax year. E-filing for the 2018 tax year was closed permanently and forever by the IRS on Oct 15, 2019. The only option that you are anyone else has if they are preparing their 2018 tax return with *ANY* do-it-yourself program, is to print, sign and mail the 2018 return to the IRS. Same holds true for any state return too, if you are required to file one.
