So you missed the April 15th filing deadline – now what?

The important thing is to remain calm and to file as soon as possible. 

The best possible scenario for you is that you're due a refund.  If that's the case and you've got money coming your way, you don't even have to file an extension.  There is no penalty for failure to file if you are due a refund. But, if you wait to file a return or otherwise claim a refund, you risk losing a refund altogether. An original return claiming a refund must be filed within 3 years of its due date for a refund to be allowed in most instances.  So if you don't file by April 15, 2016 and you're due a refund, the IRS will most likely keep your "donation".

If you owe money, better get on filing RIGHT AWAY, even if you can't afford to pay immediately.  Penalties for filing late are not nearly as bad as penalties for not paying, and the longer you wait the worse it gets.  Your balance is subject to a monthly late payment penalty and interest, so paying as soon as you can will help minimize the charges.

If you can't pay your bill in full, you should start by paying as much as you can.  The IRS offers tax payment options to help.