Itemizing vs. Standard Deduction
Taxpayers should itemize their deductions if itemizing results in a lower tax than taking the standard deduction. You can use the Persons Not Eligible for the Standard Deduction Interview Tips in the Volunteer Resource Guide, Deductions tab to help you determine if itemizing deductions would be more beneficial for the taxpayer.
Of course, those who have a standard deduction of zero should itemize their deductions. Taxpayers who normally fall into this category are taxpayers who are:
A married taxpayer, filing separately, whose spouse itemizes deductions is not allowed to claim the standard deduction; if one spouse itemizes, the other must itemize (even if the amount is "0").
In general, to benefit from itemizing their deductions, taxpayers must have mortgage interest, real estate taxes, or a very large amount of unreimbursed medical/dental expenses compared to their income.