In answer to your question, I, personally have not been investigated unexpectedly by the IRS, HOWEVER, since I worked for the IRS I was continually reviewed to ensure my returns were accurate and timely filed. To be at fault could result in termination /removal.My son, on the other hand, was recently divorced and while going through the divorce process, the IRS sent him notification that his ex-wife did not include some of her income. He was taken off guard since they used an accountant who had done her individual taxes prior to the time they were married and my son trusted her to be honest. My son had no idea she didnu2019t give that information to the accountant however, because they filed jointly, he was legally responsible for the additional tax. The problem was, she left, had not forwarding address, and said she had no job so my son was stuck with the entire amount of past-due tax, interest and added penalties. NOT FUN! I did try to help him resolve these issues and now everything is taken care of.My advice is always report all income, take all allowable deductions, have all receipts, and documentation to prove what is shown on your return and you will be fine.Just to add one more story. I had a co-worker whose husband was a long-haul trucker and they were audited unexpectedly. Since they had kept all their records with their copy of the return, the audit ended up with them receiving a nice large refund! They were unaware they could deduct some of his business expenses and the auditor took that into consideration! Needless to say, they were very happy to have been audited! (Donu2019t hear too many happy stories about audits)