These are the IRS instructions:
Assembling Your Return
Assemble any schedules and forms behind Form 1040X in order
of the “Attachment Sequence No.” shown in the upper right
corner of the schedule or form. If you have supporting
statements, arrange them in the same order as the schedules or
forms they support and attach them last. Do not attach
correspondence or other items unless required to do so,
including a copy of your original return.
Attach to the front of Form 1040X:
A copy of any Forms W-2, W-2c (a corrected Form W-2), and
2439 that support changes made on this return;
A copy of any Form W-2G and 1099-R that support changes
made on this return, but only if tax was withheld; and
A copy of any Forms 1042S, SSA-1042S, RRB-1042S, and
8288-A that support changes made on this return.
Attach to the back of Form 1040X any Form 8805 that
supports changes made on this return.
If you owe tax, enclose (do not attach) your check or money
order in the envelope with your amended return. See the
instructions for line 19, earlier
