do i have to wait until both of my returns are accepted before I can amend?

[rboie]

I accidentally filed as single when it should have been head of household. I just filed a few minutes ago and I want to change. Also, how much does it cost to amend?

[MaryK4]

You should wait until the tax returns are processed before you amend.  There are no additional fees to amend with TurboTax if you are changing filing status.  If you needed to add additional forms that required an upgrade, you would need to pay additional.    See How to File an Amended Tax Return with the IRS - TurboTax.