An extension is only an extension of time to file - not time to pay. From here, you would complete and file your tax returns when you are ready.
When you are ready to file your taxes, you can apply for an installment agreement with the IRS either directly or through TurboTax. (It is technically an application for a payment plan, but they almost always approve them).
1. You can do this directly from the TurboTax program itself. During the filing process, TurboTax will have an option for applying for an installment agreement via Form 9465 on the screen where it asks you how you want to pay your federal tax. Check the box for installment agreement and answer the questions and the form will be sent with your return.
2. You can apply for an agreement online directly with the IRS. I actually recommend you follow this route because the fees the IRS charges to set up an agreement are less with this method and you get an immediate response on your application. You can file your return as normal through TurboTax and then instead of making a payment, you will tell the program you are going to pay by check and then ignore the voucher that prints out (or you can make a partial payment with it). Then, go to the link below and file for an installment agreement with the IRS.
