The federal government sets 401(k) contribution limits for two reasons: to keep pre-tax deferrals from becoming an unlimited tax shelter, and to keep the benefit from flowing mostly to high earners. For 2026, you can defer up to $24,500 of your own pay into a 401(k), with additional catch-up room if you are 50 or older.1Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 Everything else about how the cap works follows from those two reasons.
Protecting Current Tax Revenue
Most 401(k) contributions come out of your paycheck before income tax. Every dollar you defer is a dollar the Treasury does not tax this year. Without a ceiling, a high earner could route an entire salary into the plan and owe nothing in current income tax. Section 402(g) of the Internal Revenue Code sets the maximum any individual can exclude from taxable income through elective deferrals in a given year.2Office of the Law Revision Counsel. 26 USC 402 – Taxability of Beneficiary of Employees Trust
The same annual cap covers Roth 401(k) contributions.3Internal Revenue Service. Roth Comparison Chart Roth dollars are taxed now, but they grow and come out tax-free later, so uncapped Roth contributions would still cost the Treasury significant future revenue. You can split your deferrals between traditional and Roth in any mix, but the combined total cannot exceed the annual limit.
Keeping the Benefit From Favoring Top Earners
The second reason is fairness across the workforce. Federal regulations require that 401(k) contributions not discriminate in favor of highly compensated employees, or HCEs.4eCFR. 26 CFR 1.401(a)(4)-1 – Nondiscrimination Requirements of Section 401(a)(4) For 2026, you are an HCE if you own more than 5% of the business or earned more than $160,000 from the employer in the prior year.5Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living
Each year, plans run an Actual Deferral Percentage (ADP) test comparing the average contribution rate of HCEs against everyone else. The HCE average can exceed the non-HCE average by only a narrow margin.6eCFR. 26 CFR 1.401(k)-2 – ADP Test When lower-paid workers do not participate enough, the plan fails the test, and HCEs receive refunds of the excess, which then count as taxable income. That mechanism pushes employers to encourage broad participation instead of letting the plan operate as a benefit mostly for the top of the payroll.
What You Can Actually Contribute in 2026
The individual elective deferral limit for 2026 is $24,500, up from $23,500 in 2025.5Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living It applies to you personally, not per plan. If you participate in 401(k) plans at two different employers, your combined deferrals still cannot exceed $24,500.7eCFR. 26 CFR 1.402(g)-1 – Limitation on Exclusion for Elective Deferrals Employer matching and profit-sharing dollars do not count against this cap.8Internal Revenue Service. Retirement Topics – 401(k) and Profit-Sharing Plan Contribution Limits
Catch-Up Contributions at 50 and Older
If you turn 50 or older by December 31, you can contribute an additional $8,000 on top of the standard limit, bringing your personal maximum to $32,500. You do not have to be 50 when you make the contribution; reaching that age by year-end is enough.9Internal Revenue Service. Retirement Topics – Catch-Up Contributions
SECURE 2.0 added a larger catch-up window for ages 60 through 63. If you fall in that range during 2026, your catch-up rises to $11,250, for a total personal deferral of $35,750.1Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 Once you turn 64, the catch-up drops back to $8,000.
Roth Catch-Up Rule for Higher Earners
Starting in 2026, SECURE 2.0 also changes where catch-up dollars go for higher-paid employees. If your FICA wages from your employer in 2025 were more than $150,000, any catch-up contributions you make in 2026 must go into a designated Roth account rather than a pre-tax account.5Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living At $150,000 or less, you can still choose pre-tax or Roth. The threshold is measured against wages from the specific employer sponsoring the plan, not total household income.
The Total-Contribution Ceiling
Section 415(c) sets a second, higher cap on the total annual additions to your account from all sources combined: your deferrals, employer match, profit-sharing, and any forfeitures reallocated to you. For 2026, that combined ceiling is $72,000, or 100% of your compensation, whichever is less.5Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs, as Adjusted for Changes in Cost-of-Living With catch-ups included, the effective ceiling is $80,000 at age 50 and up, or $83,250 for ages 60 through 63.8Internal Revenue Service. Retirement Topics – 401(k) and Profit-Sharing Plan Contribution Limits
Unlike the personal deferral limit, the 415(c) cap applies separately to each employer. Two unrelated jobs, two separate $72,000 ceilings. In practice, the $24,500 personal limit is the binding constraint for most workers.
Why the Numbers Change Each Year
The limits are not fixed. Section 415(d) directs the IRS to adjust them annually based on changes in the Consumer Price Index.10Office of the Law Revision Counsel. 26 USC 415 – Limitations on Benefits and Contribution Under Qualified Plans The updated figures usually appear in October or November for the following tax year. Without indexing, a static cap would quietly shrink in real terms every year and gradually undercut the retirement savings the law was designed to encourage.
What Happens If You Contribute Too Much
Because the personal deferral limit applies across all employers, going over is easiest to do when you change jobs mid-year and keep contributing at the same rate. Neither employer’s payroll system sees what you defer elsewhere, so catching the overage is on you.
If you exceed the annual deferral limit, you need to withdraw the excess by April 15 of the following year.11Internal Revenue Service. Consequences to a Participant Who Makes Excess Deferrals to a 401(k) Plan That deadline cannot be extended by filing a tax return extension. The corrective distribution has to include the excess plus any earnings on it from the year it was contributed.
Meet the April 15 deadline and the excess is taxed once, in the year you contributed it. Miss it and the same dollars get taxed twice: once when contributed, and again when eventually withdrawn from the plan. You get no basis credit to recover the double tax, and a plan that hangs on to excess deferrals without distributing them puts its own tax-qualified status at risk.11Internal Revenue Service. Consequences to a Participant Who Makes Excess Deferrals to a 401(k) Plan