1099-B from broker shows 'missing' cost basis for stock from 10+ years ago - can't remember purchase date

When brokers can't provide the cost basis information, you'll need to make a reasonable attempt to determine it yourself. Since this was purchased over 10 years ago, you have a few options: First, check if you have any old emails with trade confirmations or annual statements from TD Ameritrade. Even if you don't have the exact purchase, you might find something that helps establish a timeframe and approximate value. If that doesn't work, try contacting Charles Schwab directly. Sometimes they can access historical TD Ameritrade records that aren't visible in your online account. It's worth a phone call. As a last resort, you can make a good faith estimate. Look up historical price data for the stock during the period you think you purchased it. If you remember approximately when you bought it (even just the year), you could use the average price for that period. The IRS understands these situations happen with older investments. Whatever you decide, document your method and keep records of how you arrived at your estimate. That way, if there are any questions, you can show you made a reasonable effort.

I dealt with this exact issue last year! After going back and forth with customer service reps who couldn't help, I found this AI tool called taxr.ai that was actually super helpful. I uploaded my 1099-B and some old partial statements I had, and it analyzed everything to help reconstruct a reasonable cost basis. What I liked about https://taxr.ai was that it doesn't just guess - it looks at historical stock prices, dividend reinvestments if applicable, and even considers stock splits that might have happened. It gave me documentation to support my estimated cost basis too, which made me feel a lot more comfortable about the whole thing.

Coming back to update on my similar situation. I ended up trying taxr.ai after seeing it mentioned here, and it was actually pretty impressive. I had some vague idea I bought the stock in summer 2012, and it analyzed historical prices from that period along with the limited documentation I had. The tool gave me a detailed report showing how it calculated the estimated basis, including potential stock splits and dividend reinvestments that would have affected my basis. Having this documentation made me feel much more confident about what to report. Definitely worth checking out if you're in this situation.

If you're still struggling with this, I'd recommend trying to get an actual person at the IRS on the phone. I know, I know - sounds impossible. But I used this service called Claimyr that got me through to a real IRS agent in about 45 minutes when I had a similar issue. Go to https://claimyr.com - they basically hold your place in the phone queue and call you when an agent is about to pick up. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c When I finally got to speak with someone, they were surprisingly helpful and explained exactly how to handle my missing cost basis situation. They told me that making a reasonable estimate with documentation of my methodology was perfectly acceptable.

I have to admit I was completely wrong about Claimyr. After my skeptical comment, I decided to try it myself since I was getting nowhere with the IRS phone system. It actually worked exactly as described - I got a call back when an agent was about to answer, and I was connected directly. The IRS agent I spoke with told me that for older securities with missing cost basis, they recommend using the historical price information from the purchase period if possible. But she also said that if I document my good-faith effort to determine the basis and explain the situation in an attached statement with my return, that's acceptable. Much better than overpaying by using zero as the basis.

If you held the stock for a really long time, another approach is to check if your broker might have the purchase date, even if they don't have the cost basis. Knowing WHEN you bought it can help a lot. Then use a site like Yahoo Finance to look up the historical price on that date. Just search the ticker symbol, click on "Historical Data" and set the date range. You can then use that as your cost basis with a note explaining the situation.

Has anyone tried just calling TD Ameritrade directly? Even though they were acquired by Schwab, they might still have access to their older systems with your historical data. Sometimes these companies maintain separate record-keeping systems for years after an acquisition.

Another option if you're still stuck is to check with your tax preparer or CPA if you used one during the years around when you purchased the stock. Sometimes they keep copies of old tax returns that might have records of dividend income from that stock, which could help establish when you owned it and potentially give clues about your purchase timing. Also, don't forget to check your old bank statements if you still have access to them online. Many banks keep records going back 7+ years, and you might find the withdrawal or transfer that funded the stock purchase. Even if it doesn't give you the exact cost basis, it could help narrow down the purchase date and amount, which you can then cross-reference with historical prices. The key thing is to document whatever method you use and keep records showing you made a good faith effort. The IRS is generally reasonable about these situations when you can show you tried to find the actual information.

I went through something very similar about two years ago with an old Fidelity account. What ended up working for me was a combination approach that might help you too. First, I contacted Schwab's customer service and specifically asked to speak with someone in their "account reconstruction" department - apparently they have specialists who deal with exactly these kinds of missing cost basis issues from acquisitions. The regular customer service reps couldn't help, but this specialized team had access to more historical TD Ameritrade data than what shows up in your online account. When that didn't get me everything I needed, I used the IRS's own guidance from Publication 551. They actually have a section that covers "Unknown or Indeterminable Cost" and provides a framework for making reasonable estimates. The key is being able to show you made a good faith effort to find the actual information. I ended up creating a simple spreadsheet documenting: 1) All the places I looked for records, 2) The approximate timeframe I remembered buying (even if it was just "sometime in 2011-2012"), 3) Historical price data from that period, and 4) My reasoning for the estimate I used. I attached this as a statement with my tax return. The IRS never questioned it, and my CPA said this approach shows due diligence while being conservative about not understating the tax owed. Much better than using zero and overpaying significantly.