COLA (Cost of Living Adjustment)
Also known as: Cost-of-Living Adjustment, Inflation Adjustment
The annual inflation-based adjustment applied to dollar amounts in the federal tax code, retirement contribution limits, Social Security benefits, and other indexed thresholds. Computed from a specified CPI-U window each year.
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The Cost of Living Adjustment is the mechanism by which inflation-indexed dollar amounts in US federal law automatically adjust each year. The Internal Revenue Code requires COLA for dozens of items: federal income tax bracket thresholds, standard deduction by filing status, retirement plan contribution limits (401(k), 403(b), 457, IRA, SIMPLE IRA, SEP IRA), HSA contribution limits, FSA contribution limits, gift tax annual exclusion, estate tax exemption, foreign earned income exclusion, AMT exemption, child tax credit phase-out, EITC parameters, Saver's Credit thresholds, and many others. The Social Security Administration applies a parallel COLA mechanism to monthly Social Security benefits using CPI-W instead of CPI-U.
The IRS computes COLA each fall based on the CPI-U over a specified window (typically September of the current year for tax-year-following adjustments published in October-November). The adjustment is computed as a percentage and then applied to the prior year's limit, rounded to specific increments per item. Retirement contribution limits round to $500 for 401(k), $100 for IRA. HSA limits round to $50 self-only, $100 family. Tax bracket thresholds round to $50 or $100 depending on the bracket. The rounding can produce 'no adjustment' years where the computed percentage doesn't cross the rounding threshold even though some inflation occurred.
The annual COLA announcement comes in two coordinated releases: the IRS Notice for retirement plan limits (typically late October or early November), and the IRS Revenue Procedure for non-retirement inflation adjustments (also late October or early November). The Social Security Administration announces its benefit COLA separately in mid-October. Households should anticipate the annual changes by reviewing the prior year's adjustments and the trailing CPI-U trajectory; our [IRS 2027 contribution limits anticipation piece](/actualidad/irs-2027-contribution-limits-anticipation/) walks through the framework.
Not every dollar amount in the federal tax code is indexed for inflation. Several important thresholds have remained static for decades, eroding their real value over time. The $250,000 / $500,000 capital gains exclusion on primary residence sale (set in 1997) is not indexed and has lost roughly 50% of its real value to inflation. The Additional Medicare Tax thresholds ($200K single / $250K MFJ, set in 2013) are not indexed. The Saver's Credit income phase-out has been indexed only since 2018. The $400 self-employment tax floor (set in 1990) has lost roughly 60% of its real value. These un-indexed thresholds create gradual bracket creep that disproportionately affects middle-income households over time.
- Series I savings bonds — when the inflation-protected option fits Series I savings bonds: the inflation-adjusted yield, the $10K annual limit, the 1-year lockout, the 5-year early withdrawal penalty, and when they fit.
- Roth IRA explained: contributions, limits, withdrawals Roth IRA basics for US workers — 2026 limits, income phase-outs, the five-year rule, withdrawals, and the structural advantages.
- AGI (Adjusted Gross Income) AGI is your total gross income for the tax year minus a specific set of statutory adjustments listed on Schedule 1 of Form 1040. It is the figure on which most tax calculations and eligibility tests downstream actually operate — not your gross income, not your taxable income.
- CPI-U (Consumer Price Index for All Urban Consumers) The Bureau of Labor Statistics inflation index covering ~93% of the US population, used for cost-of-living adjustments on Social Security, federal tax brackets, IRA/401(k) contribution limits, I-bond variable rates, and most private-sector inflation indexing.
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