I had to amend a 2013 return a second time. This is what I found.
To do a second amended return you need to use the Desktop CD/Download program installed on your computer. You start with the first amended return and try to delete the 1040X and state amended forms. I couldn't make that work so I had to start over with a NEW return. You need to make a new return that would look like what the return should have looked like after the first amended. So that will become your new "original" return. You can save the real original return with a new name and update it with the changes from the first amended return so you now have a new "original" return to start with. Be sure to save several times along the way and make copies to work in, in case you need to start over and try again. THEN when you have the new "original" return you can Amend it. You will probably need to enter all the prior refunds and/or tax due payments directly on the 1040X (and on state) using the Forms mode. I had to enter both a tax due I paid on the first original return AND a refund from the 1st amended return.
