I'd been procrastinating filing my tax return just to get a $50 refund...
When to File
If you are a U.S. citizen or resident alien residing overseas, or are in the military on duty outside the U.S., on the regular due date of your return, you are allowed an automatic 2-month extension to file your return and pay any amount due without requesting an extension.
For a calendar year return,the automatic 2-month extension is to June 15.
If you qualify for this 2-month extension, penalties for paying any tax late are assessed from the 2-month extended due date of the payment (June 15 for calendar year taxpayers). However, even if you are allowed an extension, you will have to pay interest on any tax not paid by the regular due date of your return (April 15 for calendar year taxpayers).