If you used online TurboTax, you cannot do that. If you mess around with a return that you prepared using online TurboTax and make any changes, you will destroy the return forever. You could create a "dummy" return using a dummy account online and just do not file it.
If you used desktop download software you can play around as much as you want to, make copies, make changes, use the "what if" feature, etc. etc.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
