After you file

Use this IRS tool. it may want form 8606. if you are supposed to file a 1040-X all that's need would be needed is the 1040-X, 1040, and 8606 

 

https://apps.irs.gov/app/IPAR/investigate/IPAR_1/en-US/Attribute~retro_interview_complete~global~glo...