Filed your taxes? You have until midnight to mail or file your federal income tax return. Writing a check to the U.S. government may make you wonder where all the cash goes. In fiscal year 2012, the U.S. took in $2.4 trillion in taxes, $1.1 trillion (45 percent) of that in income taxes. Social Security taxes account for about $841 billion (35 percent), corporate income taxes for $237 billion (10 percent) . That's a lot of money, but the government spent $3.5 trillion, for a projected deficit of more than $1 trillion.