I have been searching for the answer and I've seen conflicting answers from different people. When amending a return, Turbotax prints out the 1040X along with a 1040 and all the schedules, and I've seen tax experts say that you should include everything when you mail the IRS (the 1040X, the amended/changed 1040, and all the schedules) but I've seen other sources say that you only send the 1040X itself plus any schedules that change. Obviously the amended 1040 itself changes, but in my case none of the schedules are different, I had just missed a 1099R which added a small amount of interest that was taxable (net additional tax was a few hundred dollars). Do you send just the 1040X? The 1040X plus the modified 1040 but not schedules? The 1040X and the whole amended return?
Also, how detailed should the 1040X explanation be? Can it just be "I missed a 1099R" or do you have to include line by line explanations?
Column B. Enter the net increase or decrease for each line
that you are changing.
Explain each change in Part III. If you need more space,
attach a statement. Attach any schedule or form relating to the
change. For example, attach Schedule A (Form 1040) if you are
amending a 2018 Form 1040 to itemize deductions. If you are
amending your return because you received another Form W-2,
attach a copy of the new Form W-2. Don’t attach items unless
required to do so.
our firm policy was 1040-x, 1040 after changes, and only other forms or schedules that changed
Do NOT send the new 1040 (that is for your use only to verify you got the amendment done correctly) ... only send the 1040X plus any forms or schedules that changed that support column B.
Read the IRS instructions here :
Assembling Your Return
Assemble any schedules and forms behind Form 1040-X in the
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. Don’t
attach a copy of your original return, correspondence, or other
items unless required to do so.
Attach to the front of Form 1040-X:
• A copy of any Form W-2, Form W-2c, or Form 2439, Notice to
Shareholder of Undistributed Long-Term Capital Gains, that
supports changes made on this return;
• A copy of any Form W-2G, Certain Gambling Winnings, or
Form 1099-R that supports changes made on this return, but
only if tax was withheld; and
• A copy of any Form 1042-S, Foreign Person's U.S. Source
Income Subject to Withholding; Form SSA-1042S, Social
Security Benefit Statement (Nonresident Aliens); Form
RRB-1042S, Payments by the Railroad Retirement Board
(Nonresident Aliens); or Form 8288-A, Statement of Withholding
on Dispositions by Foreign Persons of U.S. Real Property
Interests, that supports changes made on this return.
So the first answer says you include both the 1040X and the amended 1040, but not the schedules? The second answer says not to include the 1040. (This is what I mean by inconsistent answers.)
The best answer is to follow the IRS instructions for the Form 1040X as referenced in the answer given by Critter. The IRS instructions say to include Form 1040X, a copy of the Form 1099-R that was added to the return, and any applicable schedules.
Use the link in the answer above to read the IRS instructions for yourself.
**Mark the post that answers your question by clicking on "Mark as Best Answer"
you don't include the revised 1040 because 1040-X reflects any changes there and becomes your new tax return.
This is not stated explicitly in the instructions. instead the instructions state to include forms with an attachment seq no.
1040 does not have an attachment seq no.
in certain unusual circumstances, a form 1040 would be included with your amendment, so they don't say that you should not include it