The IRS typically releases the next year's inflation-adjusted brackets in October, in an annual revenue procedure. The 2026 figures came from Revenue Procedure 2025-32 on October 9, 2025. Until an equivalent 2027 revenue procedure is published, any 2027 threshold you see is a projection, not an official number.
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About the Author
Sujit KarkiFinance Researcher & Market Analyst
Independent finance researcher and market analyst with expertise in macroeconomics, equity markets, and personal finance. I help regular investors make better-informed decisions through rigorous, data-driven analysis.
Every fall I get the same search traffic spike for "next year's tax brackets," and every fall half the articles that show up are guessing dressed up as reporting. I'd rather tell you plainly what's confirmed, what's projected, and why the gap matters more than people assume.
Key Takeaways
The IRS had not released official 2027 tax brackets as of this writing — they typically arrive in an October revenue procedure.
2026's brackets are confirmed: seven rates (10/12/22/24/32/35/37%) and a standard deduction of $16,100 single, $32,200 married filing jointly, $24,150 head of household.
Computing the statutory formula from the actual chained-CPI series puts the 2027 adjustment at 3.0%, and that figure barely moves no matter what the final month does.
That points to a 2027 standard deduction of $16,550 single, $33,150 married filing jointly and $24,850 head of household — a projection, not an IRS figure.
One month the formula needs, October 2025, is simply absent from the published BLS series.
Any 2027 number you see before the official revenue procedure is a projection, not a citable IRS figure.
Your marginal rate and your effective rate are different numbers, and confusing them leads to bad decisions about raises, bonuses, and Roth conversions.
What actually happened
Nothing official, and that's the point of this post. The IRS adjusts federal income tax brackets, the standard deduction, and dozens of other thresholds every year for inflation, using a formula tied to the Chained Consumer Price Index. The adjustment for a given tax year is announced the preceding autumn — the 2026 figures came from Revenue Procedure 2025-32, published October 9, 2025. Following that pattern, 2027's figures should land in a similar window, roughly October 2026, likely a few weeks after this post publishes.
That timing gap is exactly why "2027 tax brackets" content proliferates every September before anything is confirmed. Search interest doesn't wait for the IRS's calendar, and neither, unfortunately, does a lot of published "guidance." I'm not going to pretend I know the exact 2027 numbers before the IRS says so. What I can do is show you the confirmed 2026 baseline and how the adjustment mechanism works, so you can sanity-check any "2027 brackets" article you encounter between now and October — including this one, once the real numbers land.
2026 single standard deduction$0
2026 MFJ standard deduction$0
2025→2026 adjustment0%Approximate average across thresholds
The math for one person
Here's the confirmed 2026 baseline, because it's the number you should actually be using to plan through the rest of this year. Seven marginal rates apply: 10%, 12%, 22%, 24%, 32%, 35%, and 37%. The standard deduction is $16,100 for single filers, $32,200 for married filing jointly, and $24,150 for head of household. Those figures already reflect the roughly 2.7% average bump from 2025 — useful context for guessing at 2027, since recent years' adjustments have clustered in a similar 2.5%–3% range as inflation cooled from its 2022 peak.
The part worth actually internalizing, independent of which year's numbers you're using, is how marginal brackets work. People routinely think a raise that pushes them "into a higher bracket" means all their income gets taxed at the new, higher rate. It doesn't. Only the income that falls within that bracket gets taxed at that bracket's rate — everything below it stays taxed at the lower rates it already qualified for. Your effective rate — total tax divided by total income — is always meaningfully below your marginal rate once you account for the standard deduction and the lower brackets underneath your top one.
Pro Tip
If you're deciding whether to take an extra freelance project, a bonus, or a Roth conversion that might "push you into a higher bracket," the real question is what your marginal rate is on that specific extra income — not what happens to your income overall, which barely moves.
Why projections aren't official
If you see a "2027 tax brackets" article citing exact dollar thresholds before roughly October 2026, ask where the number came from. There are three legitimate categories, and they're not equally reliable:
Source type
Reliability
What it actually is
IRS Revenue Procedure
Official
The only citable, final number — published once, applies to that tax year
Major tax-research "first look" estimates (e.g., Bloomberg Tax, Wolters Kluwer)
Directionally solid
Projections using the same CPI formula the IRS uses, usually released in September, close to official but not guaranteed exact
Generic "2027 tax brackets" content published mid-year
Treat with skepticism
Often a stale rehash of the prior year's numbers with the year changed, or a rough extrapolation with no methodology shown
As of this writing, no major forecaster had published complete 2027 threshold tables yet — the "first look" reports from tax-research publishers that do this work seriously typically come out in September, closer to the real announcement. Anything claiming precise 2027 numbers earlier than that deserves real skepticism about its methodology.
So I computed it myself
Telling you to be skeptical of other people's projections while offering none of
my own is a cop-out. So here is the arithmetic, run against the actual data the
IRS formula uses, with every input published.
The formula. The annual adjustment is not driven by the headline inflation
number you see in the news. That is CPI-U. The bracket adjustment uses the
Chained CPI for All Urban Consumers — C-CPI-U, BLS series SUUR0000SA0 —
averaged over the twelve months ending 31 August of the preceding year. So
tax year 2027 depends on the average of September 2025 through August 2026,
measured against September 2024 through August 2025. Different index, different
window. An article applying "about 3% inflation" from a news headline is using
neither.
The baseline. The twelve months ending August 2025 average 177.2058.
The target window, as published today:
C-CPI-U, Sep 2025 - Aug 2026 (BLS series SUUR0000SA0)
Month
Index
Status
Sep 2025
180.373
Final
Oct 2025
180.131
Absent from the series — interpolated
Nov 2025
179.889
Interim
Dec 2025
179.775
Interim
Jan 2026
180.409
Interim
Feb 2026
181.258
Interim
Mar 2026
183.193
Interim
Apr 2026
184.680
Interim
May 2026
185.771
Interim
Jun 2026
185.172
Interim
Jul 2026
185.162
Initial
Aug 2026
—
Not yet published
Two of the twelve months the formula needs are not available. August 2026 lands
in mid-September, which is expected. October 2025 is simply not in the series
at all — the published data jumps from September to November. I interpolated
it from its neighbours, which is defensible for a month sitting between two
known values that differ by less than half a point, but it is an assumption and
you should know it is there.
The result, and why the missing month barely matters. Sweeping August 2026
across a wide range of plausible outcomes:
A full percentage point of uncertainty in one month moves the annual adjustment
by less than nine hundredths of a percent. That is the arithmetic of a
twelve-month average: any single month carries one-twelfth of the weight. The
2027 adjustment is bounded between 2.999% and 3.086% across that entire sweep.
Applying that to the confirmed 2026 standard deduction requires one more step,
and it is the step most projections get wrong. The statute does not round the
adjusted amount. 26 U.S.C. §1(f)(7)(A) says:
"If any increase determined under paragraph (2)(A), section 63(c)(4)... is not
a multiple of $50, such increase shall be rounded to the next lowest
multiple of $50."
So the increase is rounded, not the total — and it rounds down, not to the
nearest. A $496 increase becomes $450, not $500.
Projected 2027 standard deduction — not official
Filing status
2026 (official)
Raw increase
Rounded down
2027 (projected)
Single
$16,100
$488
$450
$16,550
Married filing jointly
$32,200
$977
$950
$33,150
Head of household
$24,150
$733
$700
$24,850
Because the rounding discards the remainder, all three figures are identical
across the entire sensitivity sweep — every August outcome from −0.4% to +0.6%
produces the same three numbers. The statutory rounding absorbs the uncertainty
the missing month creates.
Warning
Correction, 7 September 2026. This post first gave the single-filer figure as
$16,600, and showed ranges for the other two. That used rounding to the nearest
$50 applied to the adjusted total — a convention I had inferred from the pattern
in the published 2026 figures rather than read off the statute. §1(f)(7)(A)
rounds the increase to the next lowest $50. The corrected single-filer figure
is $16,550; the joint and head-of-household figures are the low ends of the
ranges previously shown. The ranges themselves were an artefact of the wrong
method.
Warning
One genuine uncertainty remains: most months in the table above carry BLS
"Interim" or "Initial" flags and are subject to revision. This is a projection
with its uncertainties stated, which is more than most, but it is still a
projection and the IRS number in October is the only citable one.
The script that produces all of this is
scripts/project-brackets.mjs and
re-runs against live BLS data, so this section updates as the remaining months
land rather than going stale.
Run your own numbers
Interactive · marginal vs. effective rate
Your bracket isn't your tax rate
Taxable income (gross)$80,000
Filing status
Tax year
Your top bracket is 22%, but after the standard deduction and lower brackets, your effective rate on total income works out to just 11.0% — total tax of $0.
Federal income tax only — ignores payroll tax, state tax, credits, and the NIIT. Bracket thresholds are approximate to the nearest published figure; confirm exact cutoffs at irs.gov before filing. Not tax advice.
Toggle between the confirmed 2026 figures and the illustrative 2027 projection above — notice the "projected" banner doesn't disappear, on purpose. That's not a bug; it's the whole point of this post. Treat the 2027 tab as a planning estimate, not a number to file with.
Plan the rest of 2026 against the confirmed 2026 brackets, not a guess about 2027. You know exactly what applies to income you earn through December 31.
Wait for the actual IRS revenue procedure before making a 2027-specific decision — like the size of a Roth conversion — that depends on precise threshold numbers.
If you need a 2027 estimate now, use 3.0% — computed above from the actual chained-CPI series rather than guessed from headline inflation — and treat the result as a planning range, not a fact.
Recheck this post (or the IRS site directly) in October. I'll update the "projected" figures the moment the real revenue procedure lands.
Understand your own marginal vs. effective rate this year — it's the number that actually drives smart decisions about raises, side income, and conversions, and it doesn't change just because the brackets shift slightly next year.
FAQ
Frequently Asked Questions
The IRS typically releases the next year's inflation-adjusted brackets in October, in an annual revenue procedure. The 2026 figures came from Revenue Procedure 2025-32 on October 9, 2025. Until an equivalent 2027 revenue procedure is published, any 2027 threshold you see is a projection, not an official number.
Warning
Every 2027 figure in this post's calculator is explicitly labeled projected, not official. Confirm exact numbers at irs.gov once the 2027 revenue procedure is published, expected around October 2026. Not tax advice.
Sujit Karki|||8 min read