401(k) Contribution Limit 2026: Methodology and Sources

2026 constants used

• Employee elective deferral limit: $24,500
• Standard catch-up contribution age 50 and older: $8,000
• Higher catch-up contribution ages 60 to 63: $11,250
• Annual additions limit excluding catch-up: $72,000
• Compensation cap for related plan formulas: $360,000

Catch-up logic used

1. Participants under age 50 use no catch-up amount.
2. Participants age 50 and older generally use the $8,000 catch-up amount.
3. Participants ages 60 to 63 use the higher $11,250 catch-up amount.
4. The calculator adds catch-up on top of the $24,500 employee deferral limit.

Annual additions treatment

The calculator treats the $72,000 annual additions cap as the non-catch-up bucket. Employee non-catch-up deferrals, employer contributions, and other amounts that belong in the annual additions limit are compared against that cap. Catch-up contributions are then treated as a separate layer that can sit on top when the age rules allow it.

Why year-to-date deferrals are split the way they are

The tool uses the smaller of year-to-date employee deferrals or the base $24,500 limit when testing the annual additions bucket because catch-up contributions are not supposed to crowd out the $72,000 non-catch-up cap. That keeps the planning estimate aligned with the basic IRS structure instead of double-counting catch-up inside the wrong bucket.

Calculation flow

1. Determine the participant's catch-up amount from age.
2. Compute total employee cap as $24,500 plus the applicable catch-up amount.
3. Subtract year-to-date employee deferrals from that cap to estimate remaining employee room.
4. Convert the remaining employee room into an even per-paycheck target if paychecks left are entered.
5. Use the smaller of year-to-date deferrals or $24,500 as the non-catch-up employee amount when testing the $72,000 annual additions bucket.
6. Add employer contributions to that non-catch-up employee amount to estimate annual additions used.

Assumptions and limits

• The calculator assumes the user-entered year-to-date deferral amount is accurate.
• The tool does not decide whether a prior employer already used part of the annual limit correctly.
• Plan-specific true-up match rules, after-tax contribution features, and payroll election deadlines are outside scope.
• This is a planning estimate, not a plan-administration or tax-filing engine.

What the calculator does not model

This methodology does not try to reproduce every employer plan rule, every true-up formula, or every after-tax contribution feature that some plans offer. It is intentionally focused on the core IRS limit framework so users can understand the main contribution buckets before they layer in their own payroll and plan details.

Primary sources

• IRS 2026 retirement-limit announcement
• IRS one-participant and qualified-plan guidance
• IRS Publication 560

Related pages: calculator and guide.

Update policy

We update this methodology when the IRS publishes new retirement-plan limits, catch-up amounts, or plan-related guidance that changes how the 2026 rules should be summarized for planning purposes.

Interpretation note

The most useful output is not just the remaining employee room. It is understanding which bucket is binding: the employee elective deferral limit or the annual additions limit. That is usually the main planning distinction users need before they make payroll-election changes.