The standard deduction is the flat amount that filers can subtract from their income. For the 2014 tax year, it's $6,200 for single filers and $12,400 for married couples filing jointly. For the 2015 tax year, it goes up $100 for single filers and $200 for married couples filing jointly – to $6,300 and $12,600, respectively.

Matt Rourke/AP/File
Blank US Treasury checks lie on an idle press at the Philadelphia Regional Financial Center, which disburses payments on behalf of federal agencies.