Constitution

The Sixteenth Amendment: The Income Tax

The Sixteenth Amendment lets Congress tax incomes from any source without apportioning the tax among the states by population.

4Conservative Editors · Published November 8, 2026

The text

Passed by Congress July 2, 1909. Ratified February 3, 1913.

Note: Article I, section 9, of the Constitution was modified by amendment 16.

The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.

Note: Article I, section 9, of the Constitution was modified by amendment 16.

In plain English

The Amendment is a single sentence that removes one constraint.

What changed. Article I, Sections 2 and 9 required "direct" taxes to be apportioned among the states by population. A tax on incomes from property was held to be direct, which made it nearly impossible to levy in a fair way: a state with half the national population would owe half the revenue regardless of its share of the income.

What the Amendment says. Congress may tax "incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration."

What it does not say. It does not create a new power to tax. Congress already had the power to lay and collect taxes under Article I, Section 8. It does not set rates, and it does not say what an "income" is. The Amendment simply says that an income tax need not be apportioned.

The federal income tax began in earnest in 1913 and has since become the main source of federal revenue.

What the Founders said

The Founders had divided views on direct taxes. In Federalist No. 21 and No. 36, Hamilton discussed taxation by the federal government at length, and in Federalist No. 12 he noted that excises and duties on imports would likely provide most revenue. The apportionment rule protected the states from a national levy distributed without regard to their shares.

The Civil War brought the first federal income tax, in 1861 and 1862, which expired in 1872. An income tax of 1894 was struck down in 1895. Supporters of the Sixteenth Amendment in 1909 argued that the Court's decision had to be reversed, and the Amendment passed Congress in July 1909 with broad support, after President Taft proposed it as an alternative to a corporation tax of doubtful constitutionality.

It was ratified in 1913, the same year as the 17th Amendment.

How the courts have read it

  • Pollock v. Farmers' Loan & Trust Co. (1895): a tax on income from real estate and personal property was a direct tax and had to be apportioned; the decision was reversed by the Amendment.
  • Brushaber v. Union Pacific Railroad Co. (1916): the Amendment did not create a new power of taxation, and the income tax was valid.
  • Stanton v. Baltic Mining Co. (1916): the Amendment did not extend the taxing power to new subjects.
  • Eisner v. Macomber (1920): a stock dividend was not "income."
  • Commissioner v. Glenshaw Glass Co. (1955): income includes "undeniable accessions to wealth, clearly realized, and over which the taxpayers have complete dominion."
  • Moore v. United States (2024): the Court upheld the mandatory repatriation tax on the earnings of foreign corporations controlled by Americans, without deciding whether realization is required.

Why it matters now

The Sixteenth Amendment changed the relationship between citizens and the national government. An income tax gives Washington a revenue stream that grows with the economy and reaches directly into every paycheck. That is the reason the tax has been both a major source of federal funding and a recurring point of concern.

A conservative critique begins with the history. Supporters promised in 1913 that only the wealthy would pay a modest rate, and the code has become much broader and more complex. Other conservatives point out that the Amendment only removed a barrier; it was Congress that built the system, and Congress can rebuild it.

Reform proposals include simplifying the code, replacing the income tax with a consumption tax, and repealing the Amendment. The last would require an Article V process, and its advocates note that without the Amendment, Congress would still hold its other taxing powers. Whichever view one takes, the debate starts from the text: the Amendment removes apportionment and nothing more.

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