How do I file for an IRS extension (Using TT Desktop)?

You will have to print and mail the extension

Click on Federal Taxes (Personal using Home & Business)

Click on Other Tax Situations

Under Other Tax Forms

On File an Extension, click the start button

In TurboTax Desktop:

1. Open or continue your return.
2. Search for extend and select the Jump to link.
3. Answer Yes on the Applying for an Extension screen and then select Continue.
4. Follow the instructions to prepare, print, and mail your 4868 form.