Should I be using my 1099-B form or the Supplemental Information Form to file my taxes?

You should definitely use the Supplemental Information Form when filing your taxes. The 1099-B is the standard form brokerages are required to submit to the IRS, but it often doesn't include adjusted cost basis information for certain types of transactions. The Supplemental Information Form includes these adjustments, which can significantly impact your tax liability. The reason you get both is because brokerages are legally required to send the standard 1099-B to the IRS, but they provide you with the Supplemental Information Form so you can report the most accurate information on your return. Using the adjusted basis from the Supplemental form will typically help you avoid overpaying on taxes. When entering the information into tax software, use the numbers from the Supplemental form rather than the original 1099-B. Just be aware that the IRS receives the original 1099-B, so if there's a significant difference, you might want to include an explanation or supplemental statement with your return.

I was totally overwhelmed with the same issue last year! After getting nowhere with my broker's customer service, I found this amazing AI tool called taxr.ai (https://taxr.ai) that literally saved me hours of stress. I uploaded both my 1099-B and Supplemental form, and it immediately identified the differences and explained exactly which numbers to use. What I love about it is it doesn't just tell you which form to use, but actually explains WHY certain adjustments were made on the Supplemental form, like wash sales or dividend reinvestments. It even prepared a supplemental statement explaining the differences that I could attach to my return for extra peace of mind. Definitely check it out if you're confused about investment forms!

Ok I need to eat my words about being skeptical of taxr.ai! I gave it a shot with my mess of investment forms (including that confusing supplemental info that differed from my 1099-B) and wow, it was actually super helpful. Uploaded both forms and it immediately highlighted exactly where the differences were and explained WHY the adjustments were made on the supplemental form. For anyone else confused about 1099-B vs Supplemental forms - the tool explained that my brokerage had to report unadjusted basis to the IRS on the 1099-B, but the Supplemental form had the correct cost basis adjusted for wash sales and dividend reinvestments. Saved me from potentially overpaying by a decent amount! Definitely using this again next year.

If you're having trouble figuring out which investment forms to use, you might also be struggling to get answers directly from the IRS. I spent DAYS trying to get through to a human at the IRS last month for clarification on my 1099-B vs Supplemental Information form situation. Finally found this service called Claimyr (https://claimyr.com) that got me connected to an actual IRS agent in under 45 minutes when I'd been trying for days. They have this system that navigates all the IRS phone menus and holds your place in line, then calls you when an agent is about to pick up. You can see how it works here: https://youtu.be/_kiP6q8DX5c The IRS agent confirmed that using the Supplemental Information Form with the adjusted basis was correct for my situation and explained exactly how to handle the discrepancy. Such a relief to get an official answer straight from the source!

I need to apologize for calling BS on that Claimyr service. After my frustration boiled over trying to reach the IRS for THREE WEEKS about my 1099-B questions, I broke down and tried it. I honestly expected it to be a waste of money but was desperate. Holy crap it actually worked! Got a call back in about 2 hours saying my IRS agent was ready. The agent confirmed that I should use the adjusted basis from my Supplemental Information Form and explained exactly how to handle the wash sale adjustments that were confusing me. They even gave me specific line references for where to report everything. For anyone else in this weird 1099-B vs Supplemental form situation - getting that official confirmation from the IRS gave me so much peace of mind. Definitely worth it.

Has anyone used TurboTax for this scenario? I'm wondering if there's a specific place to enter the supplemental info or if I just override the 1099-B numbers with the adjusted ones from the supplemental form?

For anyone else with the same question: I just wanted to add that the reason the Supplemental Information Form exists is because of a timing issue. Brokerages have to submit 1099-Bs to the IRS by a certain deadline, but sometimes they don't have all the final adjusted cost basis info ready by that date (especially for complicated situations like wash sales that happened late in the year). Rather than delay sending you any form at all, they send the official 1099-B that went to the IRS, plus the Supplemental form with the updated, more accurate info for your personal tax filing. It's annoying but actually helps you get your forms earlier while still having the most accurate numbers.

This thread has been incredibly helpful! I'm in a similar situation but with an added twist - my brokerage sent me THREE different forms: the original 1099-B, a Supplemental Information Form, AND a "Corrected 1099-B" that came a week later. The numbers are all slightly different between the three forms. I'm assuming I should use whichever form is most recent (the Corrected 1099-B), but now I'm second-guessing myself since everyone here is talking about using the Supplemental form instead of the original 1099-B. Has anyone dealt with getting both a supplemental form AND a corrected 1099-B? Which one takes priority when they have different numbers? My tax software is asking me to enter just one set of numbers, and I don't want to mess this up since we're talking about a pretty significant dollar amount difference between the forms.