Can I amend my return from itemized to standard after I have already filed?

[Rachel_W]

Yes, you can Amend your return from Itemized to Standard Deduction.   

Note: TurboTax automatically chooses to use the higher of the Standard Deduction or your Itemized Deductions.

You can click here for instructions on Amending your tax return: How to Change a Tax Return You Already Filed.