If the IRS is questioning this then a 1099-S was issued ... look in the pile of paperwork the closing company sent home with you ... that is probably where it is hiding since they usually do not mail it out in January like a W-2.
If you completed the home sale worksheet in the program then you can print it out and send it with an explanation that it was your personal residence and you did not profit more than $250K ($500K married) so you don't owe any taxes. In the program, if you knew you had a 1099-S, you just needed to click the box to have this be reported on the Sch D to avoid the IRS letter.
