回複：Efile了,如何取得你的報稅記錄(稅單)

you are right. In any case (E-filing or paper filing) you should keep a hard copy of the return or print out a hard copy to be a permanent record for yourself.

If you have a lose, you can amend your 1040 to get your tax paid in prior year back which may create a significant benefits for you. To amend your 1040, you have to have the original records.