I'm trying tofile and wait for my amount due letter from the IRS in the mail but TurboTax won't even let me file without selecting a payment method

[IsabellaG · Accepted solution]

You do have to indicate how you will pay for your tax. You're required to pay for your tax by 04/18/2017.  You can choose to pay by check, or you can even request an installment plan. See the screenshot below. If you don't pay by the due date, eventually the IRS will send you a bill, but that will come after the due date, and you will have a penalty for failure to pay. 

If you choose to pay by check, it's your responsibility to pay by the due date, so if you choose to wait and miss the deadline, you can do that, but you must choose a payment method to file.