The Internal Revenue Service is the nation's tax collection agency and administers the Internal Revenue Code enacted by Congress. The IRS is a bureau of the Department of the Treasury and one of the world's most efficient tax administrators. In fiscal year 2017, the IRS collected $3.4 trillion and processed more than 245 million returns. The IRS Mission is to provide America's taxpayers top quality service by helping them understand and meet their tax responsibilities and enforce the law with integrity and fairness to all.