When you add up the itemized deductions on Schedule A of your tax return (medical, taxes, interest, etc.), compare the total to your adjusted gross income (AGI) from page 1 of your 1040.
Judging from the past practices of the IRS, if these deductions top 45 percent of your AGI, you’re very likely to be audited. If they top 35 percent, your audit chances are still above average.
Don’t let these guidelines stop you from taking legitimate deductions but be prepared for scrutiny. You can attach a statement to your return explaining why you had to pay so much for, say, medical expenses; this upfront statement may prevent a wider examination of your return.