ratified on february 3, 1913, the sixteenth amendment (amendment xvi) to the united states constitution allows the congress to impose a federal income tax. this allows the federal government to collect a tax on personal income, no matter where that income came from. the sixteenth amendment overturned the 1895 supreme court landmark decision in "pollock v. farmers' loan &amp; trust co". in "pollock", the court ruled that a 2 percent tax on incomes over $4,000 was unconstitutional. this was because the law the ruling struck down did not allow for apportionment, the court ruled against it. the sixteenth amendment allowed congress to levy a uniform direct income tax without being subject to apportionment.