401(k) Excess Deferral Deadline: April 15 Correction Required

What Happened

Retirement savers who contributed too much to their 401(k) or 403(b) plans during 2025 face an April 15, 2026 deadline to correct the error. Financial advisor Ian Berger from Ed Slott and Company highlighted this critical deadline in a recent analysis, warning that failure to act results in double taxation on excess contributions.

The maximum pre-tax and Roth elective deferrals for 2025 were $23,500, with additional catch-up contributions of $7,500 for those age 50 and older, or $11,250 for those aged 60-63. These limits apply across all 401(k) and 403(b) plans combined, creating potential problems for workers who participated in multiple plans during the year due to job changes or multiple employment situations.

The issue primarily affects individuals who worked for multiple employers during 2025, as each plan administrator cannot track contributions made to other employers’ plans. Workers with only one plan typically avoid this problem because plan administrators automatically prevent excess contributions, and when failures occur, the plan bears responsibility for corrections.

What It Means

The aggregation rule for retirement plan contributions creates significant compliance challenges for mobile workers. When someone changes jobs mid-year or maintains multiple employment relationships, they must personally track total contributions across all plans to avoid exceeding annual limits. This responsibility shift from plan administrators to individual participants increases the risk of inadvertent violations.

Double taxation occurs when excess deferrals remain uncorrected past the April 15 deadline. The excess amount gets taxed twice: once when contributed (since it exceeded the deductible limit) and again when eventually distributed from the plan. This penalty structure makes timely correction essential for affected workers. The correction process involves a “corrective distribution” that includes the excess contribution plus any earnings or minus any losses attributable to that excess.

The tax reporting requirements add complexity to the correction process. Excess deferrals must be included in 2025 taxable income, potentially requiring amended tax returns for those who already filed. Any earnings on the excess amount become taxable in 2026. Plan participants receive two separate 1099-R forms in early 2027: one documenting the excess deferrals already reported as 2025 income, and another for earnings reportable as 2026 income. This split reporting timeline requires careful record-keeping and coordination with tax preparation.

Estate planning implications emerge when retirement account balances include improperly handled excess contributions. Accounts with unresolved excess deferrals carry forward tax complications that can affect beneficiaries. The double taxation penalty reduces the account’s effective value for inheritance purposes, as beneficiaries may inherit accounts with embedded tax problems stemming from uncorrected excess contributions.

The 457(b) plan exception provides some relief for government and nonprofit employees. Contributions to 457(b) plans do not count toward the aggregated limit that applies to 401(k) and 403(b) plans. This separation allows eligible workers to maximize contributions across different plan types without triggering excess deferral issues, though they must still monitor contributions within each plan type separately.

Plan administrators play different roles depending on the circumstances. Single-plan participants benefit from automatic monitoring systems that prevent excess contributions. However, when multiple plans are involved, the burden shifts entirely to participants. This creates an information gap where plan administrators cannot provide complete guidance about total contribution limits across all of a participant’s retirement accounts.

Context from SimplyTrust

Retirement account management intersects with comprehensive estate planning in several important ways. Properly structured trusts can serve as beneficiaries for retirement accounts, providing continued tax-deferred growth and distribution control for heirs. However, accounts with unresolved excess contribution issues may complicate trust administration and reduce the effectiveness of estate planning strategies.

The SimplyTrust platform helps families organize their complete financial picture, including retirement account information that trustees and beneficiaries need for proper estate administration. Understanding contribution limits and correction procedures becomes part of the broader financial literacy that supports effective estate planning decisions.

Source: Act Quickly to Avoid Double Taxation on Excess 401(k) Deferrals – Ed Slott and Company, LLC