If you contribute more than the annual 401(k) limit, the excess amount gets taxed twice — in the contribution year and again in retirement. The fix is simple: request a corrective distribution before April 15 of the following year.
2026 Contribution Limits
| Limit Type | Under 50 | Age 50-59 | Age 60-63 | Age 64+ |
|---|---|---|---|---|
| Employee contribution | $23,500 | $31,000 | $34,750 | $31,000 |
| Employer + employee total | $70,000 | $77,500 | $81,250 | $77,500 |
| Catch-up contribution | — | $7,500 | $11,250 | $7,500 |
How Over-Contributions Happen
| Scenario | How It Happens |
|---|---|
| Two jobs in one year | Each employer withholds separately; combined exceeds limit |
| Mid-year job change | Old and new employer both contribute |
| Year-end payroll timing | Bonus or extra paycheck pushes over the limit |
| Catch-up eligibility confusion | Under 50 but had catch-up amount withheld |
| HR error | Payroll system set up incorrectly |
The Double Taxation Problem
$2,000 over-contribution, 22% bracket:
| Scenario | Year of Contribution | Year of Withdrawal | Total Tax |
|---|---|---|---|
| Corrected before April 15 | $440 (taxed normally) | $0 | $440 |
| NOT corrected | $440 (taxed as income) | $440 (taxed again) | $880 |
Without correction, the excess $2,000 gets taxed twice — you pay $440 extra over the life of the account.
How to Fix It
| Timeline | What to Do | Outcome |
|---|---|---|
| Before December 31 | Ask employer to reduce remaining contributions | Easiest fix — excess never happens |
| Before April 15 (next year) | Request “return of excess contributions” from plan admin | Excess + earnings returned; taxed once |
| After April 15 (next year) | Cannot undo — excess stays in the plan | Double taxation applies |
Corrective Distribution Process
| Step | Action |
|---|---|
| 1 | Contact your plan administrator (HR or custodian) |
| 2 | Request a “return of excess deferrals” under IRC §402(g) |
| 3 | Plan calculates the excess plus allocable earnings |
| 4 | Excess + earnings distributed to you |
| 5 | Include the excess as income on your tax return for the contribution year |
| 6 | Include the earnings as income for the year distributed |
Special Situations
| Situation | What Happens |
|---|---|
| Two employers | Each employer only tracks their own plan. YOU are responsible for monitoring total contributions across all employers |
| Roth 401(k) excess | Same limit applies ($23,500 combined traditional + Roth 401(k)) |
| Employer match | Employer match does not count toward the $23,500 employee limit |
| After-tax contributions | Different from employee deferrals; have their own sub-limit within the $70,000 total |
| 403(b) + 401(k) | Combined share the same $23,500 employee limit |
The Bottom Line
If you over-contributed to your 401(k), contact your plan administrator ASAP and request a return of excess contributions before April 15 of the following year. This avoids the double taxation penalty. If you work multiple jobs, track your total contributions across all employers — each employer only monitors their own plan.
Related: What Happens If You Withdraw 401(k) Early? | What Happens If You Exceed Roth IRA Contribution Limit?