I have itemized deductions greater than the standard deduction, on my federal taxes. Why is TurboTax not itemizing my MN State return?

Check your SALT deductions.   Are you sure you are itemizing on the federal return?   Check line #12 of Form 1040.   SALT is an acronym for State & Local taxes.   The law limits the deduction of state and local income, sales, and property taxes to a combined, total deduction of $10,000. The amount is $5,000 for married taxpayers filing separate returns. Taxpayers cannot deduct any state and local taxes paid above this amount.    So, you may have already been maxed out on that deduction.    Other itemized deductions are also limited.   

When you itemize deductions, you can choose to deduct either state and local taxes (SALT) or your sales taxes paid during the year.   The SALT deduction (which is either state/local income tax plus property tax OR sales tax plus property tax) is capped at $5,000 for married couples filing separately and $10,000 for all other filers. In 2017 and earlier, there was no cap.

Here's an example that compares the changes.    

Minnesota allows the larger of itemized deductions or the standard deduction. Taxpayers may claim itemized deductions on the Minnesota return even if the standard deduction was claimed on the federal return.   Minnesota has enacted the following allowable itemized deductions.

• Medical and dental expenses over 10% of Minnesota AGI.

• Real estate taxes, less any refunds or rebates received during the tax year, and personal property taxes [limited to $10,000 ($5,000 MFS)]

• Other taxes.

• Home mortgage interest.

• Investment interest expense.

• Charitable contributions.

• Casualty or theft loss. Complete Schedule M1CAT - Casualty and Theft.

• Unreimbursed employee expenses. See Schedule M1UE, Unreimbursed Employee Business Expenses.

• Other miscellaneous deductions