<prompt> Human: This is an account that was opened in 2011. Stocks were transferred into it from another brokerage. All was well and good. In 2015 I sold some of the old stocks. I dutifully printed off the 1099 and handed it to my tax man, who did my return. I did not notice, because I had no idea what I was looking at, that the brokerage did not include a basis, and the entire amount was listed as a capital gain. I offer this as an example of how not to do things. I did not notice that the basis was not there. I should only be taxed on the earnings. At least I can find the historical price, and I will now have to amend at least one return. The rules changed in 2011, and the brokerage was supposed to capture a basis. But no. At least I did see the error on the 2017 statement. fwiw, the brokerage says they dont make those kinds of changes, and that its my problem to find the basis. Yay for online tools that let you look them up. I will start checking all the other returns since 2011. Hopefully 2015 is the only one to fix. I offer myself as an example, in hopes that I can save someone else an amendment ...  <response>: This is because you sold a noncovered security, one that was purchased before brokers were required to track basis on your behalf. Consider using a different tax preparer next time, however - they seriously dropped the ball by not alerting you to the missing basis. And always read your return before signing off. 