IRS 2027 inflation adjustments tracker: what the CPI has decided

The Bureau of Labor Statistics published the August 2026 Consumer Price Index on Friday, September 11, at 8:30 a.m. Eastern. For most people it was one more inflation headline. For a specific list of 2027 tax numbers it was the closing bell: the law defines the inflation adjustment as an average of twelve monthly index values ending in August, and August was the twelfth. With that figure in the database, the 2027 tax brackets, the standard deduction, the health FSA cap, the annual gift exclusion, the estate exemption and the Medicare IRMAA thresholds are no longer forecasts. They are arithmetic waiting for the IRS and the Social Security Administration to type them up, which they will do sometime between mid-October and November.

The chained index came in at 185.739, up 0.31 percent from July and the first monthly rise since May. That single reading did what this page said it would do on September 6: it lifted most bracket thresholds one $50 step above the flat-August projection, pushed two IRMAA tiers over their rounding lines, and left the gift exclusion, the FSA cap and the single standard deduction exactly where they were already headed. One ambiguity survives the release, because one of the twelve months does not exist at all: the government was shut when it should have been measured, and nobody in Washington has said how the gap will be handled. This page tracks all of it, with the statute, the data, and a check that the method reproduces the 2026 figures the IRS actually published.

The statute picks the window, not the IRS

The core rule is in 26 U.S.C. §1(f). Paragraph (3) defines the cost-of-living adjustment as the percentage by which “the C-CPI-U for the preceding calendar year” exceeds the index for a base year, and paragraph (6) defines that measure precisely: “The C-CPI-U for any calendar year is the average of the C-CPI-U as of the close of the 12-month period ending on August 31 of such calendar year.” For tax year 2027 the preceding calendar year is 2026, so the window runs from September 2025 through August 2026. The index is the Chained Consumer Price Index for All Urban Consumers, BLS series SUUR0000SA0, which the Tax Cuts and Jobs Act substituted for the regular CPI-U in 2018 because it grows a little more slowly.

Each dollar amount then has its own base year and its own rounding rule, and the differences matter at the margin:

Item	Statute	Base year substituted	Rounding
Bracket thresholds where the 22 % bracket and higher end	§1(j)(3)(B)(i)	2017	Down to $50 ($25 single and MFS)
Top of the 10 % and 12 % brackets	§1(j)(3)(B)(i), as amended by OBBBA	2016	Down to $50 ($25 single and MFS)
Standard deduction ($15,750 single, $23,625 HoH; joint is double the single figure)	§63(c)(7)	2024	Down to $50
Health FSA salary-reduction cap ($2,500)	§125(i)	2012	Down to $50
Annual gift exclusion ($10,000)	§2503(b)(2)	1997	Down to $1,000
Estate and gift basic exclusion ($15,000,000)	§2010(c)(3)(B)	2025	Nearest $10,000
Roth IRA and IRA deduction phase-out ranges	§408A(c)(3)(D), §219(g)(8)	2005	Nearest $1,000
Medicare IRMAA thresholds ($85,000 / $107,000 / $133,500 / $160,000)	42 U.S.C. §1395r(i)(5)	12 months ending August 2018, regular CPI-U	Nearest $1,000

Two footnotes to that table. First, the One Big Beautiful Bill Act gave the 10 percent and 12 percent brackets an extra year of inflation by moving their base year back to 2016 while leaving the higher brackets on 2017; that is why the top of the 12 percent bracket grew faster than the rest in the 2026 tables. Second, for base years before 2017 the statute splices the old CPI-U series onto the chained one: §1(f)(3)(B) multiplies the base-year CPI by the ratio of the 2016 chained index to the 2016 regular index, which works out to 0.5698. That is how a 1997 base, a 2005 base and a 2012 base can be compared with a 2026 chained-index reading.

Equally important is what is not in this window. The 401(k) deferral limit and the IRA contribution limit use the third-quarter average of the regular CPI-U under §415(d), and the September print of October 14 closed that window; our 2027 401(k) and IRA projection shows the result, a 401(k) limit of $25,500 determined by a third-quarter average of 335.279 against a threshold of 334.67. The Social Security COLA uses the third-quarter CPI-W, tracked on the 2027 COLA page, and the figures the SSA indexes to wages rather than prices, from the quarter of coverage to the earnings test, have their own 2027 Social Security figures tracker. The 2027 HSA limits were published by the IRS in May, because §223(g) uses a twelve-month period ending in March. This page covers the September-to-August family only, and one member of that family that is easy to miss: the Roth IRA and IRA deduction phase-out ranges share the window and the base-year splice, so the August print settled them too. They have their own page, the 2027 Roth IRA and IRA deduction phase-outs, which runs the same check against the 2026 figures.

Checking the method against the 2026 numbers

A projection method is worth exactly as much as its ability to reproduce a number that is already public. Rev. Proc. 2025-32, released October 9, 2025, set the 2026 figures. Running the statute on the September 2024 to August 2025 window reproduces every one of them, with one instructive wrinkle.

The chained-index values BLS publishes today for that window average 177.206. Using that figure, the 2026 bracket thresholds come out one $50 step too high in most cases. Using 177.11 instead, every threshold in the revenue procedure appears exactly, across all three filing-status tables:

2026, married filing jointly	Rev. Proc. 2025-32	Method, window average 177.11
10 % bracket ends	$24,800	$24,800
12 % bracket ends	$100,800	$100,800
22 % bracket ends	$211,400	$211,400
24 % bracket ends	$403,550	$403,550
32 % bracket ends	$512,450	$512,450
35 % bracket ends	$768,700	$768,700
Standard deduction (single / joint / HoH)	$16,100 / $32,200 / $24,150	$16,100 / $32,200 / $24,150
Health FSA cap	$3,400	$3,400
Annual gift exclusion	$19,000	$19,000

The reason for the wrinkle is that BLS revises the chained index for roughly a year after first publication, and the IRS evidently uses whatever values are in hand when it writes the revenue procedure in September. The values it used in September 2025 were about 0.05 percent lower than the revised ones the database shows now. The lesson for 2027 is that the IRS will use the “initial” and “interim” values BLS published through September 11, not the finals that will replace them next February, and those are the values this page uses. The single-filer table, with its $25 rounding, and the head-of-household table reproduce the same way.

The IRMAA check is cleaner because the regular CPI-U is not revised. The twelve months ending August 2025 average 319.205, the August 2018 base window averages 249.280, and applying that ratio to $85,000, $107,000, $133,500 and $160,000 and rounding to the nearest $1,000 gives $109,000, $137,000, $171,000 and $205,000, which are exactly the 2026 thresholds CMS announced on November 19, 2025.

The data: twelve months, eleven values

Here is the closed 2027 window, from the BLS public API, series SUUR0000SA0 for the chained index and CUUR0000SA0 for the regular one:

Month	C-CPI-U	CPI-U (NSA)
September 2025	180.373	324.800
October 2025	not published	not published
November 2025	179.889	324.122
December 2025	179.775	324.054
January 2026	180.409	325.252
February 2026	181.258	326.785
March 2026	183.193	330.213
April 2026	184.680	333.020
May 2026	185.771	335.123
June 2026	185.172	333.952
July 2026	185.162	333.918
August 2026	185.739	334.980
Eleven-month average	182.8565	329.6563

The eleven published chained values average 182.8565, which is 1.3446 times the 2016 base window (135.993) and 1.3228 times the 2017 base window (138.237). Those two factors, applied to the dollar amounts written into §1(j)(2) in 2017, produce the 2027 brackets. The window runs 3.24 percent above the 177.11 that set the 2026 numbers, noticeably more than the 2.4 percent that separated 2026 from 2025.

Notice how little and how much August did. Because it was one of eleven months, a rise of 0.31 percent moved the window average by only 0.03 percent, from the 182.804 a flat month would have produced to 182.857. But so many thresholds were sitting within a single rounding step of the line that 0.03 percent was enough: four of the six joint bracket tops moved up one step from the projection this page carried a week ago, the second and third IRMAA tiers crossed to the next $1,000, and the estate exemption gained $20,000. What August could not do, and did not, was move the gift exclusion, the FSA cap or the single standard deduction, each of which needed a monthly swing several times larger.

The month that never happened

The government shutdown of October and November 2025 stopped price collection between October 1 and November 12. BLS resumed with the November index and has said it will not publish an October 2025 CPI. The public data series simply skips from September to November, for the chained index and the regular one alike.

The statute, though, says “the average of the C-CPI-U as of the close of the 12-month period ending on August 31.” It does not say what to do when one of the twelve is missing, and neither the IRS nor the Social Security Administration has issued guidance. The Treasury faced the same problem first, for inflation-protected securities, and on November 26, 2025 it invoked the index-contingency clause in its offering circular and announced an October 2025 figure of 325.604 for the regular CPI-U, adding that it “will not replace this index number even if BLS subsequently reports actual CPI for October 2025.” That number binds Treasury’s bond payments. It does not bind the IRS. A second agency has since gone the other way. When the Department of Health and Human Services updated the poverty guidelines in January 2026, it averaged only the eleven available months of 2025 and left October out, a choice it states on its poverty guidelines page and in its computation table (a 2025 CPI-U average of 321.943). So the two federal precedents point in opposite directions, and neither settles what the IRS will do (how that eleven-month choice carries into the 2027 poverty guidelines).

Two readings are defensible. One is to average the eleven months that exist. The other is to fill the gap with an estimate, as Treasury did; for the chained index the natural estimate is the midpoint of September and November, 180.131. Because October 2025 sat well below the spring and summer readings, including it pulls the average down, from 182.8565 to 182.6293, and the regular CPI-U window from 329.656 to 329.319. That is a difference of 0.12 percent, and here is what 0.12 percent does on the closed window:

2027 figure	Eleven-month average	October imputed
Top of 37 % bracket, joint	$793,650	$792,650
Top of 12 % bracket, joint	$104,050	$103,900
Top of 10 % bracket, joint	$25,600	$25,550
Head-of-household standard deduction	$24,950	$24,900
Estate exemption	$15,490,000	$15,470,000
Second IRMAA tier, single	$142,000	$141,000
Third IRMAA tier, single	$177,000	$176,000
Fourth IRMAA tier, single	$212,000	$211,000
Roth IRA phase-out starts, joint	$250,000	$249,000
Gift exclusion, FSA cap, single standard deduction, first IRMAA tier	unchanged	unchanged

The gap is not large in dollar terms, but it is systematic: every bracket threshold moves down by one step under the imputed reading, and the highest thresholds move by several. When the revenue procedure arrives, the first thing worth checking is which of these two columns it matches, because that will tell you how the IRS read the statute and will settle the same question for the estate exemption, the IRMAA tiers and the joint Roth range.

What August settled

With the window closed, the test for each figure is no longer what the next month might do but simply which side of a rounding line the final average landed on, and by how much.

The annual gift exclusion goes to $20,000. The unrounded 2027 figure is $20,119, against a rounding floor of $20,000; the imputed reading gives $20,094. The 2026 figure had been stuck at $19,000 because the unrounded amount was about $19,490, just short of the line, and rounding down erased almost $500 of accumulated inflation. That backlog is what makes 2027 the year it finally clears, and no treatment of October can undo it. For married couples using gift splitting, $40,000 per recipient; our Form 709 gift-splitting guide covers the filing side.

The health FSA cap goes to $3,500, and the carryover to $700. Unrounded, $3,516; floor, $3,500. The $3,550 step would have needed a window average above 184.6, which was never within reach. The carryover maximum is 20 percent of the cap under Notice 2020-33, so $700. Employers finalizing 2027 open-enrollment materials can use $3,500 with the “pending IRS confirmation” label doing very little work. The FSA limit page has the plan-year details.

The standard deduction: $16,600 single, $33,200 joint, and a head-of-household figure that depends on October. The 2024 base is 173.016, so the factor is 1.0569 and the unrounded single amount is $16,646, about $4 short of the $16,650 step. Moving up would have required an August chained index of 186.245; it printed 185.739. The joint figure is fixed by statute at twice the single one. The head-of-household number is $24,950 on the eleven-month average (unrounded $24,969) and $24,900 with October imputed (unrounded $24,938), so it is the one standard-deduction figure that waits for the revenue procedure.

The IRMAA tiers, and thirty-one cents. The regular CPI-U window averages 329.656, the factor over the 2018 base is 1.32243, and the four indexed thresholds come out at $112,407, $141,500, $176,545 and $211,589 before rounding, which is $112,000, $142,000, $177,000 and $212,000 after it. The second tier deserves a closer look: $107,000 times the factor is $141,500.31. It rounds up to $142,000 by thirty-one cents on a threshold of a hundred and forty-two thousand dollars. Had the August CPI-U printed 334.97 instead of 334.98, the tier would have stayed at $141,000. Under the October-imputed reading it does stay there, at $141,355 unrounded, and the third and fourth tiers drop to $176,000 and $211,000 as well. The first tier, $112,000 single and $224,000 joint, is safe under either reading and is the one that matters to the most people, since it is where the surcharge begins. The $500,000 single and $750,000 joint tier is not indexed at all until 2028. Our IRMAA projection page puts the surcharge amounts against these thresholds and flags the second tier as the number to check when CMS publishes in November.

Every bracket threshold. On the eleven-month average the joint table reads $25,600, $104,050, $218,250, $416,650, $529,100 and $793,650 for the tops of the 10 through 35 percent brackets; the single-filer table reads $12,800, $52,025, $109,125, $208,325, $264,550 and $661,375. Compared with the flat-August projection published here on September 6, the 12, 22, 24, 32 and 35 percent joint thresholds each moved up one or more $50 steps and the 10 percent threshold held at $25,600. The brackets and standard deduction page carries all three filing-status tables with both October readings side by side.

The estate exemption. $15,000,000 times the ratio of the 2026 window to the 2025 window, rounded to the nearest $10,000. Two things remain unsettled rather than three: the October treatment, and whether the IRS divides by the 2025 average it used last year (177.11) or the revised figure BLS shows now (177.206). Eleven months over 177.11 gives $15,486,685, or $15,490,000; over 177.206, $15,478,310, or $15,480,000. The imputed window gives $15,470,000 and $15,460,000 on the same two divisors. It is a $30,000 range on a $15 million number, which is to say it does not change anyone’s planning; the estate and gift page explains why the sunset that would have mattered never came.

The AMT. The alternative minimum tax exemption ($109,400 joint and $70,300 single in 2017 dollars) and its phase-out threshold are indexed the same way, and 2027 is the first year the new $1,000,000 phase-out threshold moves: it is multiplied by the ratio of the 2026 window to the 2025 window and rounded to $100. The method reproduces the four 2026 AMT figures on the draft Form 6251 exactly; for 2027 it gives an exemption of $144,700 joint and $93,000 single and a phase-out starting at $1,032,400 joint and $516,200 for everyone else (eleven-month reading). Both readings and the line-by-line form are in Form 6251 2026 draft: the AMT exemption now phases out at $500,000.

The 2027 tables as they stand

Central case throughout: the eleven published months averaged, October omitted. Official figures are marked; everything else is the statute applied to a closed window, awaiting the agency’s document.

Item	2026 (official)	2027 (this page)	Status
Standard deduction, single and MFS	$16,100	$16,600	Decided
Standard deduction, joint	$32,200	$33,200	Decided
Standard deduction, head of household	$24,150	$24,950 ($24,900 if October imputed)	October-dependent
Health FSA cap / carryover	$3,400 / $680	$3,500 / $700	Decided
Annual gift exclusion	$19,000	$20,000	Decided
Estate and gift exemption	$15,000,000	$15,490,000 ($15.46 to $15.49 million)	October- and divisor-dependent
IRMAA tier 1, single / joint	$109,000 / $218,000	$112,000 / $224,000	Decided
IRMAA tier 2, single / joint	$137,000 / $274,000	$142,000 / $284,000 ($141,000 / $282,000 if October imputed)	October-dependent, on the line
IRMAA tier 3, single / joint	$171,000 / $342,000	$177,000 / $354,000 ($176,000 / $352,000 if October imputed)	October-dependent
IRMAA tier 4, single / joint	$205,000 / $410,000	$212,000 / $424,000 ($211,000 / $422,000 if October imputed)	October-dependent
IRMAA top tier, single / joint	$500,000 / $750,000	$500,000 / $750,000	Fixed by statute
Roth IRA phase-out, single	$153,000 to $168,000	$158,000 to $173,000	Decided
Roth IRA phase-out, joint	$242,000 to $252,000	$250,000 to $260,000 ($249,000 to $259,000 if October imputed)	October-dependent
HSA, self-only / family	$4,400 / $8,750	$4,500 / $9,000	Official (Rev. Proc. 2026-24)
401(k) deferral / catch-up 50+ / IRA	$24,500 / $8,000 / $7,500	$25,500 / $8,500 / $8,000	Determined by the Q3 CPI average (335.279); IRS Notice in November
Social Security COLA	2.8 %	3.6 %	Official (SSA, October 14)

The joint bracket tops, against the 2026 official table:

Bracket ends	2026 (official)	2027, eleven-month average	2027, October imputed
10 %	$24,800	$25,600	$25,550
12 %	$100,800	$104,050	$103,900
22 %	$211,400	$218,250	$217,950
24 %	$403,550	$416,650	$416,150
32 %	$512,450	$529,100	$528,450
35 %	$768,700	$793,650	$792,650

And the single-filer tops, where the statute rounds to $25 rather than $50:

Bracket ends	2027, eleven-month average	2027, October imputed
10 %	$12,800	$12,775
12 %	$52,025	$51,950
22 %	$109,125	$108,975
24 %	$208,325	$208,075
32 %	$264,550	$264,225
35 %	$661,375	$660,550

More figures on the same clock

The same window drives a longer list of amounts that the revenue procedure prints further down its pages. Each has its own base year and its own rounding rule in the Code. Before trusting the arithmetic, we checked it against the 2026 edition. The first eighteen 2026 figures from Rev. Proc. 2025-32 that went into the table below are all reproduced by a single window average between 177.1105 and 177.1135, the same 177.11 that passes the bracket check earlier on this page, and every row added since was checked against its own 2026 figure on its dedicated page before it went in. The 2027 results:

Item	Statute (base year, rounding)	2026 (official)	2027, eleven-month average	2027, October imputed
Long-term capital gains 0 % rate, joint / single / HoH (single is half the joint figure)	§1(j)(5) (2017, down to $50)	$98,900 / $49,450 / $66,200	$102,100 / $51,050 / $68,350	$101,950 / $50,975 / $68,300
Long-term capital gains 15 % rate ends, joint / single / HoH	§1(j)(5) (2017, down to $50)	$613,700 / $545,500 / $579,600	$633,600 / $563,200 / $598,400	$632,800 / $562,500 / $597,650
Foreign earned income exclusion	§911(b)(2)(D) (2004, down to $100)	$132,900	$137,300	$137,100
Transit and parking fringe, per month	§132(f)(6) (1997, down to $5)	$340	$350	$350
Dependent standard deduction floor / earned-income add-on (kiddie tax bands follow the floor)	§63(c)(5) (1987 and 1997, down to $50)	$1,350 / $450	$1,400 / $500	$1,400 / $500
Additional standard deduction, aged or blind (married / unmarried)	§63(f) (1987, down to $50)	$1,650 / $2,050	$1,700 / $2,100	$1,700 / $2,100
Adoption credit maximum / phase-out start	§23(h) (2001, nearest $10)	$17,670 / $265,080	$18,250 / $273,680	$18,220 / $273,340
Gifts to a non-citizen spouse	§2523(i) (1997, down to $1,000)	$194,000	$201,000	$200,000
Educator expense deduction	§62(d)(3) (2014, nearest $50)	$350	$350	$350
Savings bond interest exclusion for education, phase-out start, single / joint	§135(b)(2) (1989, nearest $50)	$101,800 / $152,650	$105,100 / $157,600	$104,950 / $157,400
Qualified charitable distribution limit / one-time split-interest limit	§408(d)(8)(G) (2022, nearest $1,000)	$111,000 / $55,000	$114,000 / $57,000	$114,000 / $57,000
Information-return threshold (Forms 1099-NEC and 1099-MISC, backup withholding)	§6041(h) (2025, increase to nearest $100)	$2,000 (first year, not indexed)	$2,100	$2,100
Employer educational assistance exclusion (tuition and student loan payments combined)	§127(d) (2025, increase to nearest $50)	$5,250 (unchanged since 1986, not indexed)	$5,400	$5,400
Qualified long-term care distribution cap (details)	§401(a)(39)(B)(ii) (2023, increase to nearest $100)	$2,600 (Notice 2026-33)	$2,700	$2,700
Child tax credit per child / refundable maximum	§24(i) (2024 and 2017, increase down to $100)	$2,200 / $1,700	$2,300 / $1,800	$2,300 / $1,800
ABLE account annual contribution limit	§529A(b)(2)(B)(i) through §2503(b) (1996, down to $1,000)	$20,000	$20,000	$20,000
Saver’s Credit AGI limits, joint, 50 % / 20 % / 10 % (ABLE contributions only from 2027)	§25B(b)(3) (2005, increase to nearest $500)	$48,500 / $52,500 / $80,500	$50,000 / $54,000 / $83,000	$50,000 / $54,000 / $83,000
Earned income credit, maximum with 1 / 2 / 3+ children / none	§32(j) (1995, nearest $10 on the underlying amounts)	$4,427 / $7,316 / $8,231 / $664	$4,573 / $7,552 / $8,496 / $685	$4,566 / $7,544 / $8,487 / $685
Earned income credit, investment income limit	§32(j) (2020, down to $50)	$12,200	$12,600	$12,600
Student loan interest deduction, phase-out start single / joint	§221(f) (2001, down to $5,000)	$85,000 / $175,000	$90,000 / $180,000	$90,000 / $180,000
Adoption credit, refundable portion	§23(h)(3) (2024, nearest $10)	$5,120	$5,280	$5,280
QBI deduction threshold, single / joint	§199A(e)(2) (2017, down to $50; joint = 2 × single)	$201,750 / $403,500	$208,300 / $416,600	$208,050 / $416,100
QBI minimum deduction / active QBI needed	§199A(i)(3) (2025, increase to nearest $5)	$400 / $1,000	$415 / $1,030	$410 / $1,030
Section 179 dollar limitation / phase-out threshold / SUV cost cap	§179(b)(6) (2024 for the first two, 2017 for the SUV cap; nearest $10,000, SUV nearest $100)	$2,560,000 / $4,090,000 / $32,000	$2,640,000 / $4,230,000 / $33,100	$2,640,000 / $4,220,000 / $33,000
Dependent care assistance exclusion (dependent care FSA; half that for married filing separately)	§129(a)(2)(A) (not indexed)	$7,500	$7,500	$7,500
Estates and trusts: 10 % bracket ends / 37 % bracket begins (the NIIT threshold follows the second)	§1(j)(2)(E) and (j)(3)(B) (2016 for the first since the 2025 law, 2017 for the second; down to $50)	$3,300 / $16,000	$3,400 / $16,500	$3,400 / $16,500
Estates and trusts: 35 % bracket begins	§1(j)(3)(B) (2017, down to $50)	$11,700	$12,100	$12,050
Estates and trusts: capital gains 0 % ends / 15 % ends	§1(j)(5) (2017, down to $50)	$3,300 / $16,250	$3,400 / $16,750	$3,400 / $16,750
Estates and trusts: AMT exemption / phase-out start	§55(d)(3) (2011, nearest $100)	$31,400 / $104,800	$32,500 / $108,200	$32,400 / $108,100
AMT exemption add-on for a child subject to the kiddie tax	§59(j)(2) (1997, nearest $50)	$9,750	$10,050	$10,050
Covered expatriate: average annual net income tax test / exit tax exclusion	§877(a)(2) (2003) and §877A(a)(3) (2007), nearest $1,000	$211,000 / $910,000	$218,000 / $940,000	$217,000 / $939,000
Excess business loss threshold, single / joint	§461(l)(3)(C) (2024 since the 2025 law, nearest $1,000; joint = 2 × single)	$256,000 / $512,000	$264,000 / $528,000	$264,000 / $528,000
SIMPLE plan additional employer nonelective contribution, maximum per employee	§408(p)(2)(G) (2023, nearest $100)	$5,300	$5,400	$5,400
QSEHRA maximum, self-only / family	§9831(d)(2)(D)(ii) (2015, amount down to $50)	$6,450 / $13,100	$6,700 / $13,550	$6,700 / $13,500
Long-term care premium limits by age (40 or less / 41–50 / 51–60 / 61–70 / over 70) and per diem; indexed to the August medical-care CPI, so October plays no role	§213(d)(10), §7702B(d)(4) (August 1996, nearest $10)	$500 / $930 / $1,860 / $4,960 / $6,200; $430	$500 / $940 / $1,890 / $5,030 / $6,290; $440	Same

Three of these deserve their own pages. The foreign earned income exclusion has the thinnest margin of anything on this site: the unrounded eleven-month figure is $137,308.80, only $8.80 above its step (full projection and the 2026 draft Form 2555). The transit and parking limit reaches $350 under either treatment, which matters now because employees set their 2027 elections during fall open enrollment (commuter benefits 2027). The joint 0 % capital gains band clears $100,000 for the first time (2027 capital gains thresholds). Two more sit on this window even though the IRS prints them elsewhere. The qualified charitable distribution limit appears in the November retirement-plan notice next to the 401(k) limit, yet it is indexed through section 1(f)(3), not the third-quarter CPI, so it is already $114,000 (2027 QCD limit). And the new $2,000 threshold for Forms 1099-NEC and 1099-MISC, first used for 2026 payments, is indexed from 2027 with its increase rounded to the nearest $100, which puts it at $2,100 (Form 1099-NEC for 2026 and 2027). The same 2025 base now indexes the $5,250 cap on tax-free employer tuition and student loan payments, unchanged since 1986, with its increase rounded to the nearest $50: $5,400 for 2027 under either treatment of October (educational assistance limit 2027). The child tax credit, indexed since the 2025 law with its increase rounded down to $100, steps up to $2,300 per child with $1,800 refundable (child tax credit 2027); the ABLE limit, now on its own 1996 base, stays at $20,000 while the gift exclusion catches up to it, and the Saver’s Credit survives in 2027 only for ABLE contributions (ABLE limits 2027). The earned income credit table is the one place where the October question moves nearly every cell by $10 to $30 (EITC 2027 projected table); the adoption credit maximum is October-dependent too, $18,250 or $18,220, while its refundable part lands on $5,280 either way (adoption credit 2027 and the 2026 Form 8839); and the student loan interest phase-out steps up a full $5,000 to $90,000 single and $180,000 joint (student loan interest deduction 2027). The annual gift exclusion clears $20,000 by only $119 (gift tax annual exclusion 2027), the QBI thresholds and the new $400 minimum deduction both hinge on October (QBI deduction 2027), and one 2027 figure needs no CPI at all: the SALT cap is 101 % of 2026 by statute, $40,804 with the phase-down from $510,050 (SALT cap 2027). Two business and workplace figures close the list. The section 179 expensing limit reaches $2,640,000 either way, while its phase-out threshold and SUV cap are the October-dependent parts (section 179 limit 2027); and the dependent care FSA exclusion does not move at all, because section 129 has no inflation clause, so it stays at $7,500 while the health FSA cap rises (dependent care FSA limit 2027). Four more rows were added on October 4, each checked against its 2026 figure first. Trusts and estates reach the 37 % bracket at $16,500, and since the 2025 law their 10 % bracket carries one more year of inflation than the rest of the table (trust and estate tax brackets 2027); the kiddie tax threshold rises to $2,800 (kiddie tax 2027); the small-employer QSEHRA cap reaches $6,700 self-only (QSEHRA limits 2027); and the long-term care premium limits are not on this window at all but on the August medical-care index, which makes them final already (long-term care premium limits 2027). The exit tax thresholds for 2027 expatriations depend on October like most of the table (exit tax 2027), while the Roth catch-up wage threshold, which runs on the third-quarter CPI-U like the 401(k) limits, is $155,000, confirmed by the closed average (Roth catch-up wage threshold 2027).

Two of the newer rows are settled whichever way October is treated. The excess business loss threshold reaches $264,000, or $528,000 on a joint return, after the 2025 law moved its base year to 2024, which is why the 2026 figure fell below 2025’s $313,000 (excess business loss limit 2027). The cap on the extra nonelective contribution an employer can add to a SIMPLE plan reaches $5,400; the SIMPLE deferral limits themselves follow the third-quarter method, which the September CPI closed at $17,500, or $19,100 at small employers, determined and awaiting the IRS Notice (SIMPLE IRA limits 2027).

The calendar from here

• Friday, September 11, 8:30 a.m. ET. August CPI, published. The twelve-month window closed for everything in the tables above; this page was updated with the final averages and each item marked as decided or October-dependent.
• October 14. September CPI, published. It closed the third-quarter windows: the COLA, the 401(k) and IRA contribution limits, and the November I bond rate. The SSA announced the COLA at 3.6 percent the same morning; the IRS still has to confirm the plan limits in its annual notice.
• Mid-October to November. The IRS revenue procedure with the 2027 brackets, standard deduction, FSA cap, gift exclusion and estate exemption. In 2025 it came on October 9. The first check: which October column it matches.
• November. The IRS notice on retirement plan limits, including the Roth and IRA phase-out ranges (November 13 in 2025), and the CMS announcement of 2027 Part B premiums and IRMAA thresholds (November 19 in 2025). The second IRMAA tier is the line to read first.

A closing note on what this page is for. Sites that publish “2027 tax brackets” in June are guessing at an inflation rate and multiplying; the numbers here are the statute applied to the published index, checked against the last revenue procedure, with the one genuine ambiguity, October 2025, shown both ways rather than hidden inside a single figure. When the official documents land they should match one of the two columns above to the dollar. If they do not, the discrepancy is the story, and it will be explained here.

Published September 6, 2026. Updated September 13, 2026, with the August 2026 index that closed the window, and October 24, 2026, with the September CPI that closed the retirement-plan limits and the COLA. Next update: the day the IRS revenue procedure is released.