Can I claim the standard deduction on my federal return and use Schedule A (itemized deductions) for the State return?

You can file with the standard deduction on your federal return and itemize on your state return if your state allows it.  If you have to amend your return wait until your return has been processed and any refund or tax liability has been settled. . 

"Should I file an amended return before I receive my refund?"

Are you saying that you have already filed your Federal 1040 tax return?  But now you would like to amend it before you file your state tax return?

Or are you saying something else?

Some states will allow you to itemize deductions on the state income tax return even if you claim the standard deduction on the Federal 1040 tax return.  What state income tax return are you filing?

If you have already filed your Federal 1040 tax return, you need to wait until the Federal 1040 tax return has been accepted and the IRS has approved the refund (if there is one.)

But it is best to wait until you receive the refund from the IRS before you process a amended Federal 1040 tax return.

If you used TurboTax Online, log in to your account and select Amend a return that was filed and accepted.

If you used the CD/download product, sign back into your return and select Amend a filed return. 

See also this TurboTax Help.

@hprice300 

I live in the state of California and want to know if it is legal to file standard deduction on the federal return and itemize on the state return. Turbo Tax recently submitted my return and it was accepted, but it takes a couple of weeks for the refund.