Generally, yes, you need to add it to your taxes.
A 1099-B reports to you and the IRS how much you received for selling something, usually stocks or bonds.
It should tell you not only how much you received, but in many cases what your cost basis was.
Your gain or loss is the difference between what you received and your cost basis. If you are unsure about this contact the payer listed on the form for clarification.
