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6 min read · Last updated September 30, 2026

A statutory formula, not a policy vote, produced every one of the more than 60 adjusted tax numbers for 2026, using a single government price index measured the same way every year since 2018.

In this article

• What actually gets adjusted, and how often
• The formula: chained CPI, not the traditional index most people picture
• What moved for 2026, in real numbers
• What does not move
• Frequently asked questions

The Internal Revenue Service (IRS) does not decide each year whether to adjust tax brackets for inflation. A formula written into the tax code does it automatically. That same formula is why a 2.5% cost-of-living raise almost never pushes a worker into a higher bracket the way people assume it will.

What actually gets adjusted, and how often

Every fall, the IRS runs the same calculation across more than 60 separate provisions of the tax code and publishes the results in a single Revenue Procedure. For the 2026 tax year, that document was Revenue Procedure 2025-32, released October 9, 2025. It arrived alongside changes required by the One Big Beautiful Bill Act (OBBBA), the 2025 federal tax law that also touched several of these same figures. The list covers the width of each of the seven ordinary income tax brackets, the standard deduction, dozens of credit and deduction thresholds, and the estate tax exemption, among others.

For a single filer in 2026, the 22% bracket now covers income from $50,400 to $105,700, up from $48,475 to $103,350 in 2025. That $2,350 shift at the top of the bracket is the concrete result of the formula below, not a policy choice made fresh each year.

The formula: chained CPI, not the traditional index most people picture

Since the Tax Cuts and Jobs Act (TCJA) of 2017, the law has required the IRS to index tax brackets to the Chained Consumer Price Index for All Urban Consumers (C-CPI-U). That’s not the traditional CPI that gets quoted in most news coverage of inflation. The statute (26 U.S.C., the United States Code, § 1(f)(3)) defines the adjustment as the percentage by which the C-CPI-U for the preceding year exceeds a fixed 2016 baseline. Two separate paragraphs of the same section fix how each of those two figures is measured: § 1(f)(4) sets the 12-month period ending each August 31 for the 2016 baseline, and § 1(f)(6)(B) sets that identical window for the C-CPI-U figure itself.

The chained version assumes people shift their spending somewhat when prices rise unevenly, such as buying more chicken when beef gets expensive. That produces a slightly slower-growing number than the older index would. It’s a deliberate, permanent policy choice from 2017. The annual bracket bump is consistently a little smaller than headline inflation numbers suggest, not a rounding quirk.

In plain terms: if your paycheck raise is meant only to keep pace with the cost of living, the bracket edges are, by design, rising at close to the same underlying rate. That’s the actual mechanism behind the common experience of “my raise didn’t push me into a higher bracket,” and it is not luck.

What moved for 2026, in real numbers

Provision	2025	2026	Change
Single filer, top of 22% bracket	$103,350	$105,700	+$2,350 (+2.3%)
Married filing jointly, top of 22% bracket	$206,700	$211,400	+$4,700 (+2.3%)
Standard deduction, single filer	$15,000	$16,100	+$1,100 (+7.3%)
Standard deduction, married filing jointly	$30,000	$32,200	+$2,200 (+7.3%)

The bracket edges moved by about 2.3%, as the table above shows for both filing statuses. The standard deduction moved by more, a 7.3% jump, because the One Big Beautiful Bill Act (OBBBA) raised its baseline amount on top of the routine inflation math.

Reading a single year’s jump as pure inflation, without checking whether a separate law also changed the baseline, is the most common way this system gets misread.

What does not move

Not every number in the tax code is indexed. Personal exemptions have been set to $0 by statute since the Tax Cuts and Jobs Act (TCJA) took effect, and they stay there regardless of inflation. That was originally scheduled to expire, but the One Big Beautiful Bill Act (OBBBA) later made it permanent. Some credit phase-out thresholds, including the Lifetime Learning Credit’s income limits, have not been adjusted since 2020, because Congress wrote them into the statute as fixed dollar amounts rather than inflation-linked ones. A provision’s presence in the tax code does not guarantee it moves every year. Whether a specific number is indexed depends entirely on how that section of the law was written the year it was enacted. The annual Revenue Procedure will not adjust anything the underlying statute doesn’t specifically instruct it to. Reading every number in a tax-prep article as automatically current for the new year is a common mistake. The safer habit is checking whether the specific figure in question is one Congress chose to index at all. The same October announcement that resets brackets and deductions also feeds into how a tax refund is actually produced the following spring, since withholding tables are rebuilt around these same updated numbers.

Frequently asked questions

Why does the IRS announce new tax brackets in October instead of January? The law measures the Chained Consumer Price Index for All Urban Consumers (C-CPI-U) over the 12-month period ending each August 31. The Bureau of Labor Statistics then needs about six more weeks to finalize that data before the IRS can calculate the next year’s numbers.

Does a raise that matches inflation ever push someone into a higher bracket? It can, if the raise outpaces the specific chained CPI adjustment for that year, or if a large one-time bonus or side income pushes total taxable income up faster than wages alone. A raise that exactly tracks the same cost-of-living measure the brackets use will land close to the same relative spot in the bracket structure.

Is chained CPI the same number reported in most news headlines about inflation? No. Most inflation headlines cite the standard Consumer Price Index for All Urban Consumers. The tax code has used the chained version since 2018, which typically runs slightly lower over time because it accounts for consumers substituting cheaper goods when prices shift.

Do state income tax brackets adjust the same way? Not necessarily. Each state sets its own rules, and some states don’t index their brackets for inflation at all. A state bracket can stay fixed in dollar terms even in a year the federal brackets move.

What happens to a provision Congress never wrote as inflation-indexed? It stays exactly where the statute set it, no matter how much prices rise, until Congress passes a new law to change it. The personal exemption and several fixed-dollar credit thresholds are the clearest current examples.