Please be aware that an extension of time to file your return does not grant you any extension of time to pay your tax liability.
Extensions for Individuals
If you are not able to file your federal individual income tax return by the due date, you may be able to get an automatic 6-month extension of time to file. To do so, you must file Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return by the due date for filing your calendar year return (usually April 15) or fiscal year return. This form is also available en español.