Student loan interest requires a schedule not supported in the free edition.
The new "simplified" 1040 form for 2018 is now the only 1040 form. The old 1040, 1040A and 1040EZ have all been replaced with the new 1040 and 6 new schedules for additional items that are transfer to the new 1040.
https://ttlc.intuit.com/questions/4511015-what-are-the-new-schedulesThe TurboTax Free Edition only supports the basis new 1040 form and not any additional schedules. If schedules are needed then Deluxe or higher will be required depending on which schedule and types of income you have.
The Free TurboTax edition has always only supported the simplest tax form and no additional schedules. In the past there were several items that could be reported on the 1040EZ that the IRS has now eliminated and placed on an additional schedule.
Many users that used the Free Edition in the past can no longer do so because of those changes that now require Deluxe or higher.
However, if your income is under $33,000 you might be able to use the Freedom Edition for that supports all states and most forms including the new schedules.
The Freedom Edition is part of the IRS Free File alliance and is totally separate from TurboTax website.
https://turbotax.intuit.com/taxfreedom/How do I switch to TurboTax Freedom Edition?
https://ttlc.intuit.com/questions/2026912-how-do-i-switch-to-turbotax-free-file-program?jump_to=answ...
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**