Also known as Form 4868. Use Form 4868 to apply for 6 more months (4 if “out of the country” (defined on page 2) and a U.S. citizen or resident) to file Form 1040, 1040A, 1040EZ, 1040NR, 1040NR-EZ, 1040-PR, or 1040-SS.
There are three ways to request an automatic extension of time to file a U.S. individual income tax return.
1. You can file Form 4868 electronically by accessing IRS efile using your home computer or by using a tax professional who uses efile.
2. You can pay all or part of your estimate of income tax due using a credit or debit card or by using the Electronic Federal Tax Payment System (EFTPS).
3. You can file a paper Form 4868.
Here is the link for the form and instructions: