If the United States abolished the federal income tax, the government would lose more than half its revenue overnight and would need a replacement system capable of generating roughly $4 trillion a year to keep operating at current levels.1U.S. Treasury Fiscal Data. Government Revenue The leading proposal in Congress would swap income taxes for a national sales tax, but the consequences reach into retirement accounts, Social Security, Medicare, and the balance of who pays more and who pays less. And a permanent abolition would require repealing the Sixteenth Amendment, something no repeal amendment has accomplished since Prohibition ended in 1933.
The Revenue Hole
Individual income taxes account for about 53 percent of federal revenue in fiscal year 2026.1U.S. Treasury Fiscal Data. Government Revenue The federal government collected roughly $5.2 trillion in fiscal year 2025. Any serious abolition plan also targets corporate income taxes and payroll taxes, which together push the replacement burden past 80 percent of total federal revenue.
Whatever fills that gap has to work every year, in recessions and booms, without cratering federal spending on defense, Medicare, Social Security, interest on the debt, and everything else. This is the central constraint. Cutting income taxes to zero by ordinary legislation is possible, but without a funded replacement, the result is a deficit increase measured in trillions.
The FairTax and the 23 Percent Rate
The leading legislative vehicle is the FairTax Act, reintroduced in the 119th Congress as H.R. 25. It would repeal individual and corporate income taxes, payroll taxes, and estate and gift taxes, and replace them with a national retail sales tax starting in 2027. It would also abolish the IRS and hand most administration to the states.2GovInfo. HR 25 – FairTax Act of 2025
The proposed rate is 23 percent, calculated tax-inclusive. On a $100 purchase, $23 goes to the government and $77 goes to the seller. Expressed the way state sales taxes usually work, as a percentage added on top of a sticker price, the effective rate is closer to 30 percent ($23 รท $77).3Congress.gov. Text – HR 25 – 119th Congress – FairTax Act of 2025 Both figures describe the same tax.
Whether a 23 percent retail sales tax can actually raise the required revenue is disputed. Supporters point to the broader base, which would include housing, healthcare, and services typically outside state sales tax systems. Critics point to retail-level evasion, the political inevitability of carve-outs, and reduced consumer spending at higher prices. No developed country funds its entire government through a single retail sales tax at this scale.
The Prebate
To blunt the hit on low-income households, the FairTax includes a monthly “prebate,” an advance rebate sized to cover the sales tax a household would pay on spending up to the federal poverty level. For 2026, the poverty level for a family of four is $33,000.4HealthCare.gov. Federal Poverty Level FPL At a 23 percent rate, that household would receive roughly $7,590 per year, about $632 per month.
Who Pays More, Who Pays Less
The current income tax is progressive: rates rise with income, and low earners pay little or nothing. A flat-rate consumption tax works the other way. Lower-income households spend nearly all of what they earn, so a sales tax reaches close to 100 percent of their income. Higher-income households save and invest a larger share, and money that is invested rather than spent on retail purchases is not taxed at the point of sale.
The prebate offsets this at the bottom by making poverty-level spending effectively tax-free. It does not close the gap for middle-income households who spend most, but not all, of what they earn. Proponents argue the shift is partly balanced by eliminating payroll taxes, which are themselves regressive because they apply only to earned income up to a cap, and by projected economic growth. Those growth projections are contested.
Investment income deserves its own note. Capital gains, dividends, and interest would no longer be taxed federally. For households with substantial portfolios, that is a large tax cut that a consumption tax only partially recaptures.
Social Security and Medicare
Payroll taxes fund almost all of Social Security and Medicare Part A. In 2024, payroll taxes accounted for about 90 percent of Old-Age and Survivors Insurance income, 97 percent of Disability Insurance income, and 88 percent of Hospital Insurance income, with total payroll tax revenue across these programs exceeding $1.68 trillion.5Social Security Administration. Trustees Report Summary
The FairTax addresses this by dedicating part of the 23 percent rate to these programs. The headline rate breaks down as a 14.91 percent general revenue rate plus separate rates earmarked for old-age, survivors, disability insurance, and hospital insurance.3Congress.gov. Text – HR 25 – 119th Congress – FairTax Act of 2025 Trust fund revenue would come from sales tax receipts rather than paychecks. Payroll taxes rise and fall with employment; consumption tax revenue rises and falls with consumer spending, which drops sharply in recessions. That is a different kind of volatility than these trust funds currently absorb.
Retirement Accounts and Investments
Traditional 401(k)s and IRAs are built around a specific bargain: contributions go in pre-tax and withdrawals are taxed as ordinary income later. Abolish the income tax and the second half of that bargain vanishes. Anyone who spent decades contributing to a traditional account gets a deduction going in and owes nothing coming out. That is a windfall for current retirees and near-retirees.
Roth accounts run the other way. Roth IRA and Roth 401(k) holders paid income tax on their contributions in exchange for tax-free withdrawals. If withdrawals were going to be tax-free anyway, they paid taxes they did not need to pay. No clean transition rule fixes this asymmetry without picking winners and losers.
Investment returns that get reinvested rather than spent escape federal taxation entirely under a pure consumption tax. For households whose wealth grows primarily through appreciation and reinvestment, the effective federal tax rate falls substantially.
The IRS and Enforcement
The FairTax would end appropriations for IRS operations after fiscal year 2029 and require destruction of federal income tax records by the same deadline, except records needed for Social Security benefits or ongoing litigation.3Congress.gov. Text – HR 25 – 119th Congress – FairTax Act of 2025 A new Sales Tax Bureau inside Treasury would take over federal-level administration, with states handling most collection.
Enforcement shifts from monitoring the wages, investments, and deductions of hundreds of millions of individuals to auditing retail transactions at a smaller universe of businesses. That is a narrower target, but retail sales tax fraud, including underreported sales, off-the-books operations, and fabricated business-to-business exemptions, is a documented problem in countries that rely heavily on consumption taxes.
Why It Requires a Constitutional Amendment
The Sixteenth Amendment, ratified February 3, 1913, gives Congress power to tax incomes “from whatever source derived, without apportionment among the several States.”6Constitution Annotated. Sixteenth Amendment As long as it stands, ordinary legislation can drop income tax rates to zero, but the next Congress can raise them back. Permanent abolition means repealing the amendment.
Repeal requires proposing a new amendment (two-thirds of both chambers of Congress, or two-thirds of state legislatures requesting a convention) and ratification by three-fourths of the states, which today means 38 out of 50.7Constitution Annotated. Article V – Amending the Constitution No state-called convention has ever been successfully convened.8Congress.gov. The Article V Convention for Proposing Constitutional Amendments The only amendment ever to repeal another is the Twenty-First, which ended Prohibition in 1933.
The FairTax builds this constraint into itself. If the Sixteenth Amendment is not repealed within seven years of the bill’s enactment, the entire sales tax system expires automatically, and the Sales Tax Bureau shuts down within six months of that date.3Congress.gov. Text – HR 25 – 119th Congress – FairTax Act of 2025 The sunset exists to prevent Congress from stacking a national sales tax on top of a restored income tax.
What States Without Income Tax Show
Eight states levy no individual income tax. They fund themselves through some combination of sales taxes, property taxes, severance taxes on natural resources, and other revenue. None of them lacks a sales or property tax as well. They shifted the burden; they did not eliminate taxation.
State-level abolition is far easier than federal. A single legislature can do it through ordinary law if the state constitution allows, and several states have passed phase-out laws that use revenue triggers to lower rates automatically when surpluses hit set targets. States that drop income taxes lean harder on sales and property taxes, which shifts costs toward consumption and real estate. Whether that works depends heavily on the state’s economic base. Oil revenue and tourism dollars fill the gap more easily than a broad-based economy funding schools and public safety.
The federal version has no comparable escape valve. There is no severance tax on national oil production large enough to matter, no tourism base sized to the federal budget, and no easy path back if the replacement underperforms. That is why the debate over abolishing the federal income tax is really a debate about what replaces it, who ends up paying, and whether the math holds up outside a spreadsheet.