Can I go back into turbotax to help figure out how much money I should convert from my 401K to Roth IRA for 2019 so I do not get bumped up to a higher tax bracket?

[Critter]

For On-Line version
You appear to be using the TTax On-Line version.  Unfortunately the on-line version does not support a 'what-if' scenario (that is only available with the desktop version).

Once you make ANY changes to the online version the previous information is overwritten and is PERMANENTLY deleted.  You will have to manually re-enter/re-create your return.

Try these tools:

http://www.irs.gov/Individuals/IRS-Withholding-Calculator

 https://turbotax.intuit.com/tax-tools 

http://turbotax.intuit.com/tax-tools/calculators/taxcaster

[SweetieJean]

Remember state taxes as well.