Do I need to sign both the 1040X and 1040 for my amended return?

You only need to sign the Form 1040X. The updated 1040 is just an attachment that shows the corrections, but the 1040X is the actual form being processed for your amendment. The 1040X is essentially telling the IRS "here's what I originally filed, here's what it should have been, and here's the difference." The signature on the 1040X covers the entire amendment package, including any attachments. Make sure you attach any supporting documents related to the 1099-R for the Roth conversion. Even though it's not a taxable event, it's good to include documentation that explains the rollover.

I went through this exact situation last year with a missed Roth conversion. Was pulling my hair out trying to figure out what to attach until I found taxr.ai (https://taxr.ai). Uploaded my forms and tax docs there and it immediately spotted the Roth conversion issue and walked me through exactly what forms needed signatures. Saved me hours of research and potential errors. Their system specifically highlighted that only the 1040X needs a signature while the supporting 1040 is just an attachment. The guidance was super clear about what supporting docs to include for the IRS to properly process non-taxable event rollovers.

Just wanted to follow up on my K-1 amendment question. I ended up trying taxr.ai and it was incredibly helpful. I uploaded my original return and the missed K-1, and it generated a complete checklist of what forms needed to be updated and included with my 1040X. What impressed me most was the specific guidance on non-obvious impacts - my K-1 had some foreign tax credits that affected forms I wouldn't have thought to update. The system flagged all of these connections and explained where each number needed to go. Saved me from what would have definitely been a second amendment later! Also confirmed that only the 1040X needs signing, not the supporting documents. My amendment is now submitted and I'm actually confident it's correct this time.

If you're still struggling with getting a straight answer from the IRS about your amendment requirements, I'd recommend trying Claimyr (https://claimyr.com). I was in a similar situation with amendment questions that weren't clearly addressed in the instructions, and spent WEEKS trying to get through to the IRS phone line with no luck. Used Claimyr and got connected to an actual IRS agent in about 15 minutes instead of the usual 2+ hour wait (if you even get through at all). You can see how it works in this demo: https://youtu.be/_kiP6q8DX5c The agent confirmed that for amended returns, you only sign the 1040X form, not the supporting 1040. They also gave me specific guidance on exactly what supporting documents I needed for my particular situation, which saved me from potential processing delays.

I take back what I said about Claimyr being sketchy. After waiting on hold with the IRS for literally 3 hours yesterday only to have the call dropped, I decided to try it out of desperation. The service actually worked exactly as described. Their system called me back about 30 minutes later, and when I picked up, I was already connected with an IRS representative! No waiting on hold at all on my end. The agent confirmed I only needed to sign the 1040X and not the supporting 1040 for my amendment. For anyone still wondering about the original question - the official word from the IRS rep was that you ONLY sign the 1040X form. The supporting 1040 and other forms just need to be attached without signatures since they're supporting documents, not the official forms being submitted for processing.

Make sure you write "COPY - DO NOT PROCESS" at the top of that revised 1040 when you send it in! This helps prevent confusion at the IRS processing center. I didn't do this once and it caused a major headache when they tried processing both returns.

Don't forget to check your state return too! If you're amending federal for a missed 1099-R, you might need to amend state as well, even for non-taxable events. Some states require reporting of all 1099-Rs regardless of taxability.

Great question! Just went through this exact process last month with a missed 1099-R for a Roth conversion. You only need to sign the 1040X form - that's the official amendment document. The revised 1040 is just supporting documentation to show what the corrected return looks like. One tip I wish I'd known earlier: make sure to include a brief explanation letter with your amendment explaining that this was a non-taxable Roth rollover that was simply omitted from the original filing. This helps the IRS processor understand the context and can speed up processing. Also double-check that you're reporting the rollover in the correct section of your 1040 - it should go in the IRA distributions section with the taxable portion marked as $0. The IRS gets confused when the reporting doesn't match their records from the 1099-R. Your amendment should be straightforward since there's no tax impact, but getting all the documentation right upfront will save you potential follow-up letters from the IRS.