In the United States, you may be able to deduct a percentage of your treatment costs from your federal taxes if you meet certain requirements. To deduct medical expenses, you have to list every deduction you are taking. This is called "itemizing" your deductions. Itemizing deductions is the opposite of taking the standard deduction, an amount based on your filing status: for 2011 returns, $5,700 for a single person, $11,400 for a married couple filing jointly.
If your itemized deductions add up to more than the standard deduction, it's to your advantage to itemize. If your itemized deductions are less than the standard amount, it's not to your advantage to itemize.
Your itemized deductions include a number of other expenses besides your medical costs: state and local income taxes, mortgage interest and real estate taxes, charitable contributions, and certain work-related expenses.
Itemizing deductions can be complicated and there are many rules based on your income and filing status. To ensure that you're including everything that you can and nothing that you can't, you may want to talk to a tax preparation expert or a certified public account. The American Institute of Certified Public Accountants has a tax planning section that may provide helpful information.