Generally, you must decide whether to itemize deductions or to use the standard deduction. You should itemize deductions if your allowable itemized deductions are more than your standard deduction. Some taxpayers must itemize deductions because they do not qualify for the standard deduction.

Those taxpayers not eligible to use the standard deduction include nonresident aliens, dual-status aliens, and individuals who file returns for periods of less than 12 months. When a married couple files separate returns and one spouse itemizes deductions, the other spouse must also itemize deductions. For additional information, refer to IRS Publication 501, Exemptions, Standard Deduction, and Filing Information.

What Are Itemized Deductions?

Itemized deductions are certain expenses that you can use to lower your taxes. The categories of itemized deductions are:

1. Medical and dental expenses,
2. State and local income taxes, or sales tax,
3. Real estate and personal property taxes,
4. Home mortgage and investment interest,
5. Charitable contributions,
6. Casualty and theft losses,
7. Job expenses, and
8. Miscellaneous deductions.

Limitations on Itemized Deductions

You may be subject to a limit on some of your itemized deductions based on your adjusted gross income. Refer to IRS Form 1040 Instructions (PDF) for these limitation amounts. This limit applies to all itemized deductions except medical and dental expenses, casualty and theft losses, gambling losses, and investment interest.

For more information on itemized deductions compared to using the standard deduction, refer to IRS Form 1040, Schedule A and B (PDF), or IRS Publication 17, Your Federal Income Tax.