401k Contribution Limits 2027: IRS Limits and Key Changes

The 401k contribution limit for 2027 is the maximum amount you can defer from your paycheck into a workplace retirement plan that year. The IRS has not published the 2027 figures yet — they normally arrive in late October or early November 2026 — so this guide explains how the limits are calculated, the announced 2026 amounts that serve as the starting point, and a transparent projection of where 2027 is likely to land. It is written for anyone planning payroll deferrals, an employer match, or a max-out strategy.

{{IMG_1:Clean editorial illustration of a stepwise annual contribution limit ladder with a rising indexed bar chart and neutral palette, 16:9}}

What the 401k Contribution Limit Actually Covers

"401k contribution limit" is shorthand for four separate caps that apply to the same plan. Keeping them apart prevents most planning mistakes.

The elective deferral limit is the one most people mean. It applies only to money that comes out of your pay. The catch-up sits on top of it and does not count toward the total annual additions cap. The total annual additions limit, often called the 415(c) limit, is the ceiling for everything that lands in the account from all sources except catch-up contributions. The compensation limit caps the salary your employer uses when it calculates a match.

Figures change every year and should be confirmed at IRS.gov before you act. The 2026 amounts above are the announced figures; the 2027 amounts are not official until the IRS publishes its annual cost-of-living notice.

How the IRS Indexes 401k Limits Each Year

The indexing formula

Each limit is a base-year dollar amount multiplied by the cumulative change in the chained Consumer Price Index for All Urban Consumers and then rounded down to a statutory unit:

where $B_{base}$ is the statutory base amount, ${\text{CPI}}_t$ is the four-quarter average chained CPI-U ending in the third quarter of the prior year, and $r$ is the rounding unit for that specific limit.

The rounding units decide whether a limit moves at all:

• Elective deferral: rounded down to the next lower multiple of $500
• Catch-up: rounded down to the next lower multiple of $100
• Total annual additions: rounded down to the next lower multiple of $1,000
• Compensation limit: rounded down to the next lower multiple of $10,000

A worked example

Suppose the relevant chained CPI-U increase is 2.6% and the current deferral limit is $24,500:

Rounding down to the next lower multiple of $500 gives $25,000. Because the statute indexes from a fixed base year rather than from last year's published limit, a figure can jump by more than one rounding step in a single year — which is how a catch-up limit moves by $500 rather than $100.

2027 401k Contribution Limit Projection

Because the limits are indexed, the useful question is not "what will inflation be?" but "how much inflation is needed to push the current limit past the next rounding step?" That threshold is simple to compute.

The threshold math for the elective deferral limit

So if the 12-month chained CPI-U change is at least about 2.04%, the 2027 elective deferral limit becomes $25,000. The next step up requires far more:

Only above roughly 4.08% would the limit reach $25,500.

Likely 2027 outcomes

Applying the same logic to the other limits:

• The 50+ catch-up needs roughly 1.25% inflation to move from $8,000 to $8,100, so $8,100 or $8,200 is the most probable 2027 figure.
• The 60-63 catch-up is 150% of the standard catch-up, so it would land near $12,150 if the standard catch-up becomes $8,100.
• The total annual additions limit needs about 1.39% to reach $73,000 and about 2.78% to reach $74,000, making $73,000 the most likely 2027 value.
• The compensation limit needs about 2.78% to reach $370,000; otherwise it stays at $360,000.

Key changes that affect 2027 planning

The 2027 numbers are not only about inflation. A few rules land around the same period and change how you can use the limits:

• Roth catch-up requirement. Catch-up contributions must be made as Roth contributions for participants whose prior-year wages from the sponsoring employer exceeded an indexed threshold (roughly $145,000 to $150,000). Plans were required to comply for plan years beginning after 2025, with transition relief for some, so 2027 is the first clean year for many payroll systems.
• Age-based higher catch-up. For participants who reach age 60, 61, 62, or 63 during the year, the higher catch-up applies instead of the standard one.
• Automatic enrollment. Newly established plans generally must enroll eligible employees automatically, which changes default deferral rates.
• No legislation required. The limits rise automatically with inflation, so a projection is a math exercise, not a policy forecast.

How to Calculate Your Own 2027 Contribution

Step 1: pick a dollar target

where $P$ is your annual pay counted for plan purposes and $r$ is your deferral rate. On $120,000 of pay at a 10% rate, $C_{\text{employee}}=12,000$, well under a projected $25,000 limit.

Step 2: convert the target into a per-paycheck amount

To max out a projected $25,000 over 26 paychecks, $d=25,000/26\approx 961.54$ per paycheck. Against a per-paycheck gross of about $4,615.38, that is a deferral rate of roughly 20.83%.

Step 3: check the employer side against the total limit

If your employer matches 50% of pay up to 6%, a $120,000 salary produces a match of $0.06\times 120,000\times 0.5=3,600$. Combined with a $25,000 deferral, total annual additions are 28,600 — far below a projected $73,000 cap. Only plans that allow after-tax contributions can realistically approach that ceiling, and catch-up contributions sit outside it entirely.

Run your own pay and match figures through the retirement calculator, then check long-run growth with the compound interest calculator.

Step-by-Step: Planning Around the 2027 Limits

1. Confirm your plan's deferral rules, match formula, and payroll cutoffs. Some plans cap deferrals as a percentage of pay.
2. Check the current-year limit first, since January 2027 paychecks may still follow your 2026 election until payroll updates.
3. Choose a percentage or a flat dollar amount. A flat dollar amount avoids overshooting the limit; a percentage is easier to maintain.
4. Leave a buffer for bonus or commission pay, which can push you past a flat-dollar target set for base pay only.
5. Recheck the official figure when the IRS publishes it in the fall of 2026, then adjust your election for the following January.
6. Model the long-run effect, not just one year. A future value calculator shows what a steady annual contribution becomes over decades, and a coast FIRE calculator helps you test whether you could stop contributing earlier.

Common Mistakes and Limits of This Projection

• Treating the deferral limit as the total cap. Employer dollars and after-tax contributions have their own ceiling.
• Counting catch-up contributions toward total annual additions. They are excluded.
• Assuming the deferral limit is per employer. The elective deferral limit applies across all plans you participate in during the year, while the total annual additions limit applies per unrelated employer.
• Forgetting that front-loading can cost match dollars. If your plan does not true up, contributing the full amount by mid-year may reduce the employer contribution.
• Treating a projection as an official number. The 2027 values here are estimates built from the published indexing method, not IRS announcements.
• Reading a limit as advice. A contribution limit is a tax rule, not a recommendation about how much to save or where to invest.

FAQ

What is the max 401k contribution for 2026?

For 2026, the employee elective deferral limit is $24,500. Participants aged 50 or older can add an $8,000 catch-up, for $32,500 in total employee deferrals. Participants who reach age 60 through 63 during the year can use the higher catch-up, set at 150% of the standard amount. Total annual additions from all sources, excluding catch-up, are capped at $72,000.

When will the IRS announce the 2027 401k contribution limits?

The IRS typically publishes retirement plan cost-of-living adjustments in late October or the first week of November of the preceding year, so the 2027 limits are expected in the fall of 2026. The announcement usually appears as a news release followed by the formal notice.

Is the 2027 401k contribution limit official yet?

No. Until the IRS publishes its notice, every 2027 figure is a projection. Because the limits are indexed and rounded down in fixed increments, the projected range is narrow: the deferral limit is most likely $25,000, with $24,500 or $25,500 as the plausible alternatives.

Does the 401k contribution limit include my employer's match?

No. Employer contributions count against the separate total annual additions limit, which is $72,000 for 2026 and is projected to be around $73,000 for 2027. Catch-up contributions are excluded from that total.

Do catch-up contributions count toward the total annual additions limit?

No. Catch-up contributions sit outside the 415(c) limit, which is why a participant using the full catch-up can have more than the published total annual additions figure land in the account in one year.

Put the Numbers to Work

Before the official 2027 figures arrive, the useful step is knowing your own numbers: your pay, your deferral rate, your employer's match formula, and how many paychecks remain. Run them through the retirement calculator and the take-home pay calculator to see how a change in deferral rate affects both your retirement balance and your paycheck. Both tools are free, use transparent formulas, and require no account.