Do I need to attach my federal extension form when I e-file both my federal and state tax returns?

The IRS already knows that you filed an extension request for tax year 2021, Form 4868, if you e-filed or printed and mailed the extension request.  The form is not filed with the 2021 tax return.

No you do not have to attach any forms if you requested an extension.   If the IRS accepted your  extension request then they already know it.   Just file the return normally.  You have until mid-October to e-file; after that e-filing will close.

When you requested your extension you were supposed to pay your estimated tax due.  Did you enter the payment you made into your tax return?  Go to Federal>Deductions and Credits>Estimates and Other Taxes Paid>Other Income Taxes 

Thanks so much - great point on entering payment into the system (if one was made)

So one quick follow up - Can i file my state return as normal efile through turbotax as well?  or do i need to attach an extension somehow as well?   both my federal and state returns are in a refund situation 

thank you again !

Yes you can file both federal and state normally.   E-filing is available until mid-October.  If you are getting a refund it does not matter whether you have an extension.