Like a root canal or cross-country move, the prospect of having your tax return audited makes most people panic.
"Nearly everyone has an extreme phobia about IRS audits," said Brian Stoner, a CPA in Burbank, California. "The only exceptions are those who have been audited, and the audit went well."
Generally, the IRS can examine returns that you've filed in the last three years, but it can dig even further back for substantial errors.
You may need to provide copies of documents to substantiate the income, credits and deductions you claimed, including receipts, bills and canceled checks.
Here are five things you may not know about how the IRS chooses its targets.