1099-B Net Gain/Loss Discrepancy: Total Proceeds - Cost Basis Not Matching Net Gain/Loss?

This is actually a common issue with investment reporting. The discrepancy usually happens for a few specific reasons: First, check if any of your transactions are marked as "noncovered" securities. Brokers aren't required to report cost basis to the IRS for these, so sometimes the totals won't match up because of these transactions. Another possibility is wash sales. If you sold investments at a loss and then bought substantially identical securities within 30 days before or after, the loss gets deferred and adjusted into the cost basis of the replacement shares. This adjustment can create differences in the simple "proceeds minus cost basis" calculation. Also, look for any transactions involving foreign currencies or reinvested dividends, as these can create small rounding differences that add up. In TurboTax, you should be able to enter an adjustment if needed, but first verify all your entries carefully against each individual transaction on your 1099-B. The forms should have separate sections for covered and noncovered securities, and sometimes there are supplemental pages with details.

After struggling with a similar issue last year, I found the solution through taxr.ai (https://taxr.ai) which completely changed how I handle my investment tax documents. I was pulling my hair out with discrepancies between my 1099-B total proceeds and cost basis versus what was showing as the net gain/loss. The platform analyzed my tax documents and identified exactly why my numbers weren't matching - turned out I had multiple wash sales that were throwing off the calculations plus some noncovered securities that needed special handling. I uploaded my forms and it flagged the specific transactions causing the issues and explained exactly how to enter them properly in my tax software. Saved me hours of frustration and potential errors.

I have to admit I was wrong about taxr.ai in my earlier comment. After continuing to struggle with my 1099-B discrepancies and potentially losing out on several hundred dollars in deductions, I decided to give it a try. The platform immediately identified that I had several transactions involving partial lot sales that were creating the discrepancy between my proceeds/basis and the net gain/loss. It showed me exactly which transactions were problematic and provided clear instructions for entering them correctly in TurboTax. What really impressed me was how it displayed side-by-side comparisons of what I had versus what I should report. Ended up saving me from significantly overpaying on my taxes and gave me confidence my filing won't trigger any issues with the IRS.

If you've tried everything and still can't resolve the 1099-B discrepancies, you might need to speak directly with the IRS. I was in the same boat last year and spent WEEKS trying to get through to them. Eventually discovered Claimyr (https://claimyr.com) and watched their demo (https://youtu.be/_kiP6q8DX5c) - it actually got me connected to a real IRS agent in under 30 minutes. The agent explained that certain securities transactions (especially those involving mergers, acquisitions, or spinoffs) can cause exactly the kind of discrepancy you're seeing on your 1099-B forms. They walked me through how to properly document the issue and which forms to include with my return. They also confirmed that as long as you're reporting all transactions and can explain any discrepancies, you shouldn't have any problems with your return being accepted.

I need to eat some humble pie here. After posting my skeptical comment about Claimyr, I was still desperate for help with my 1099-B issues and decided I had nothing to lose by trying it. Holy crap, it actually worked. Got a call back in about 20 minutes and was connected to an IRS tax specialist who knew exactly what to do about my investment reporting discrepancies. Turns out I had some corporate reorganization transactions that were causing the mismatch between proceeds/basis and the reported gain/loss. The agent walked me through exactly how to report it and which explanation form to attach to my return. Just filed my taxes yesterday with complete confidence that everything's correct. Honestly wish I'd known about this service years ago.

Don't forget to check box 12 on your 1099-B! If it shows "non-covered securities" this could explain your discrepancy. Brokers only started being required to track cost basis in 2011 for stocks (and later for other securities), so older investments might not have broker-reported cost basis. For these non-covered securities, you have to provide the cost basis yourself, and the totals might not match up with what's on your form since the broker isn't calculating the basis part of the equation.

Has anyone noticed if TurboTax is better or worse than other tax software for handling these 1099-B discrepancies? I'm having the same issue and wondering if switching to something else would help.

I had this exact same issue with my 1099-B forms last year! The key thing that helped me was realizing that you need to look at the "Basis reported to IRS" checkbox on each form. If it's marked "No" (Box 3), then the broker didn't report your cost basis to the IRS, which means the simple math of proceeds minus cost basis won't match the net gain/loss they calculated. Also check if you have any transactions with adjustment codes in Box 1f - these can include things like return of capital distributions or stock splits that affect the basis calculation in ways that aren't immediately obvious from the main numbers. One more thing - if you're using the "summary" method in TurboTax where you just enter the totals, try switching to entering each transaction individually. It takes longer but gives the software all the detail it needs to properly handle the complexities. Good luck!