The Sixteenth Amendment gives Congress the power to tax income “from whatever source derived” without having to divide the tax among the states by population. In plain terms, the 16th Amendment income tax authority reaches wages, business profits, interest, dividends, rents, royalties, capital gains, and almost any other economic gain a person receives, but only once that gain is realized and only to the extent Congress has chosen to tax it in the Internal Revenue Code. The full text is a single sentence: “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.”1Congress.gov. U.S. Constitution – Sixteenth Amendment
What the Amendment Actually Did
A common misconception is that the Sixteenth Amendment created the federal power to tax income. It didn’t. Congress had that power all along. The problem was a Supreme Court decision, Pollock v. Farmers’ Loan & Trust Co. (1895), which held that a tax on income from property (rents, bond interest, and similar earnings) was a “direct tax” and therefore had to be apportioned among the states by population under Article I, Section 9.2Justia U.S. Supreme Court Center. Pollock v. Farmers’ Loan and Trust Co.3Constitution Annotated. ArtI.S9.C4.1 Overview of Direct Taxes Apportionment made a uniform national income tax nearly impossible to administer, because the total tax owed by a state depended on its census count rather than the incomes of its residents.
The Supreme Court spelled out the amendment’s narrow effect in Brushaber v. Union Pacific Railroad (1916), explaining that the amendment “does not purport to confer power to levy income taxes in a generic sense—an authority already possessed and never questioned” but was “drawn for the purpose of doing away for the future with the principle upon which the Pollock Case was decided.” So the amendment severed the link between income taxes and the apportionment rule. It did not create a new taxing power, reclassify income taxes, or expand what counts as income. It just removed the constitutional obstacle Pollock had built.
What “From Whatever Source Derived” Covers
Congress took the amendment’s language at its word. Section 61 of the Internal Revenue Code defines gross income as “all income from whatever source derived” and lists fourteen categories, including compensation for services, business income, gains from property sales, interest, rents, royalties, dividends, annuities, pensions, and income from the discharge of debt.4Office of the Law Revision Counsel. 26 USC 61 – Gross Income Defined The list is explicitly “not limited to” those categories, so virtually any economic gain is taxable unless a specific provision of the code excludes it.
In practice, that default sweeps in gambling winnings, prizes, barter transactions, found property, and canceled debts. The IRS does not need Congress to name each new form of economic benefit. If you received something of value, it is taxable unless you can point to a code section that says otherwise.
Different Rates for Different Kinds of Income
The amendment treats all income sources equally as a constitutional matter, but Congress taxes different kinds of income at different rates. For 2026, ordinary income (wages, business profits, interest) is taxed under seven brackets ranging from 10 percent to 37 percent.5Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Long-term capital gains, from assets held longer than a year, are taxed at 0, 15, or 20 percent depending on taxable income. Short-term capital gains, on assets held a year or less, are taxed at ordinary rates. Nothing in the Sixteenth Amendment requires this split. It is a policy choice Congress is free to make, unmake, or restructure.
The Realization Requirement: What the Amendment Does Not Reach
The most important limit on the amendment’s reach comes from how courts have read the word “income.” In Eisner v. Macomber (1920), the Supreme Court defined income as “the gain derived from capital, from labor, or from both combined” and held that the gain must be “severed from” the capital before it counts as taxable income. The Court was blunt: “Mere growth or increment of value in a capital investment is not income.” This is the realization requirement.
The practical consequence is large. If you buy stock for $10,000 and it grows to $50,000, the $40,000 increase is not taxable while you hold the stock. Only when you sell does the gain become realized and taxable. Investors can defer tax indefinitely by holding appreciated assets, and heirs who inherit those assets often receive a stepped-up cost basis that erases the unrealized gain entirely.
The realization question came back before the Court in Moore v. United States (2024), which considered whether Congress could tax shareholders on the undistributed profits of a foreign corporation they partially owned. The majority upheld the tax but deliberately dodged the bigger question, ruling only that Congress may attribute an entity’s realized income to its shareholders, similar to how partnerships and S corporations already work. Whether Congress can constitutionally tax purely unrealized gains, such as the paper appreciation of stock you have not sold, remains an open question the Court explicitly declined to answer.
What Isn’t Taxed: Statutory Exclusions
The “from whatever source derived” language sets a wide default, but the Internal Revenue Code carves out dozens of specific exclusions. These exclusions exist because Congress decided certain receipts should not be taxed, not because the Sixteenth Amendment lacks the reach to cover them. Three matter to millions of taxpayers.
Gifts and inheritances are not included in the recipient’s gross income. Income the gifted property later generates (dividends, rent, interest) is fully taxable, but the transfer itself is not.6Office of the Law Revision Counsel. 26 USC 102 – Gifts and Inheritances
Life insurance death benefits paid because of the insured’s death are generally excluded from the beneficiary’s gross income. Exceptions apply when a policy has been transferred for valuable consideration or when the beneficiary receives installment payments and earns interest on the deferred amounts.7Office of the Law Revision Counsel. 26 USC 101 – Certain Death Benefits
Interest earned on bonds issued by state and local governments is excluded from federal gross income. Certain private activity bonds and arbitrage bonds are not covered, but the exclusion reaches the vast majority of municipal debt.8Office of the Law Revision Counsel. 26 USC 103 – Interest on State and Local Bonds
The point of these exclusions is what they show about the structure. The Sixteenth Amendment defines the outer boundary of what Congress can tax. The Internal Revenue Code determines what Congress does tax.9Internal Revenue Service. Tax Code, Regulations and Official Guidance The gap between those two lines is where tax policy lives, and it can be redrawn by any Congress willing to amend the code.
Arguments That the Amendment Is Invalid
A persistent strain of argument claims the Sixteenth Amendment was never properly ratified because of clerical variations in how individual state legislatures recorded their approval, or that the Constitution otherwise does not authorize an income tax. Federal courts have rejected these claims every time they have been raised. The IRS classifies arguments that “the Constitution does not authorize an income tax” as patently frivolous, and federal courts have imposed penalties of up to $25,000 on taxpayers who raise them in litigation.10Internal Revenue Service. The Truth About Frivolous Tax Arguments – Section III
Filing a return that relies on these theories, or refusing to file on that basis, exposes the filer to the frivolous-return penalty and potential criminal prosecution on top of the tax and interest owed. Whatever the appeal of the argument, the cost of losing it is real, and the argument has never won.