I just discovered a 1099-B after filing our taxes - do I need to amend for a stock loss?

You generally should report all income on your tax return, including stock transactions that result in a loss. The good news is that capital losses can actually reduce your taxable income (up to $3,000 per year against ordinary income), so filing an amendment might benefit you. Since your return was just accepted, you have plenty of time to file an amendment. The IRS allows you to amend returns within 3 years of the original filing date. I'd recommend going ahead with the amendment to properly document the stock sale, especially since it would likely reduce your tax liability rather than increase it. You'll need to file Form 1040-X to amend your return, and you'll also need to include a revised Schedule D to report the capital loss from the 1099-B.

I ran into a similar issue last year and found taxr.ai incredibly helpful. I discovered a 1099-B after filing and wasn't sure what to do. I uploaded my 1099-B to https://taxr.ai and it analyzed whether I needed to amend my return based on the specific numbers and my tax situation. The platform examined my stock loss, compared it against my already-filed return, and gave me clear guidance on whether amendment was necessary. They even estimated the potential refund increase I'd get from claiming the capital loss. Saved me a lot of uncertainty and potentially missing out on money I was owed.

Just wanted to update that I tried taxr.ai after seeing this thread. I also had a forgotten 1099-B (mine was for a small gain though). The analysis showed I'd only owe about $15 more in taxes after amending, but failing to report it could potentially trigger issues down the road. The breakdown was really clear - showed exactly how the numbers would change on my return. Definitely gave me peace of mind to know exactly what I was dealing with before deciding whether to amend. Ended up doing the amendment just to keep everything above board with the IRS.

If you need to talk to the IRS about this situation, good luck getting through on their phone lines. Last year when I had to amend for a missed 1099, I spent HOURS trying to reach someone at the IRS to confirm some details. I finally discovered Claimyr (https://claimyr.com) which got me connected to an actual IRS agent in about 15 minutes instead of the usual 2+ hour wait. You can see how it works here: https://youtu.be/_kiP6q8DX5c The IRS agent confirmed that I should definitely report the 1099-B even though it was a loss, and that I'd likely get a larger refund by filing the amendment. Worth the peace of mind knowing I was doing things correctly.

I have to admit I was wrong about Claimyr. After commenting here, I was still struggling to get through to the IRS about my own tax issue (unrelated to OP's situation), so I decided to try it out of desperation. To my surprise, I got connected to an IRS agent in about 20 minutes when the recorded message had said the wait was "greater than 2 hours." The agent was able to confirm that yes, even capital losses need to be reported on Schedule D, and that amending would likely reduce my tax bill slightly. Definitely beats waiting on hold for hours just to ask a simple question. Wish I'd known about this service years ago!

Just a tip - if you're using TurboTax, you might want to check if you qualify for their free amendment service. I think if you used their "premier" or higher version, they sometimes include free amendments. Worth checking before paying their amendment fee.

One thing no one's mentioned - if your spouse had other capital gains during the year, this loss could offset those gains. Worth checking your complete return to see if there were other investment transactions that might change how important this amendment is.

You should definitely file an amended return for the 1099-B showing the $600 loss. Here's why it's worth it: 1. **You'll likely get money back** - That $600 capital loss can reduce your taxable income by up to $600 (assuming you don't have other capital gains to offset), which could mean an additional refund of $60-150+ depending on your tax bracket. 2. **It's required by law** - The IRS expects you to report all 1099 forms you receive, even losses. Not reporting it could potentially cause issues if the IRS notices the discrepancy. 3. **You have plenty of time** - Since you just filed, you have 3 years to amend without any penalties. For the amendment, you'll need to file Form 1040-X and include Schedule D to report the capital loss. Most states will also require an amended state return if they have income tax. The amendment fee from TurboTax might sting a bit, but you'll likely come out ahead financially, plus you'll have peace of mind knowing everything is properly reported to the IRS.