TurboTax Online saves only the most recent version of your tax return. There is no backout or undo, no "Save As" or any other way to save multiple versions, and no way to exit without saving. All changes are saved immediately and permanently.
The CD/Download TurboTax software does have "Save As." You can save multiple versions of your tax return with different file names, so you can experiment or do what-ifs without affecting your actual tax return.
