You don't need MAX benefits (or Deluxe Edition) to amend your tax returns from previous years. Any tax return filed using TurboTax can be amended up to 3 years past the filing of the return.
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***