Tax season is here. Dave Johnson, attorney with Johnson & Lane in Knoxville, says that medical expenses are deductible, but there is a 7.5% floor. That means that you must have paid 7.5% of your annual income before you can deduct this expense. Medical insurance is only deductible if it is not pre-tax. For example, if you have an income of $100,000, the first $7500 in medical expense that you pay is non-deductible. He says the biggest itemized deductions are mortgage interest, Iowa tax and charitable contributions.