Can I Max Out Both a 401k and 403b?

Many workers have access to employer-sponsored retirement plans like the 401(k) and the 403(b). The 401(k) is offered by for-profit companies, while the 403(b) is available to employees of public schools, certain non-profit organizations, and churches. Individuals who can contribute to both plans simultaneously, such as from working two jobs, often have questions about how much can be saved and what rules govern contributions across the different plans.

The Shared Employee Contribution Limit

An individual cannot contribute the maximum employee deferral amount to both a 401(k) and a 403(b) plan in the same calendar year. Both plan types are subject to a single, combined contribution limit for employee contributions, governed by Internal Revenue Code Section 402(g). For 2025, this shared employee contribution limit is $23,500. This means the sum of all personal contributions to both a 401(k) and a 403(b) cannot exceed this figure.

This shared limit is a personal cap, regardless of how many employers or plans an individual has. For instance, if an employee contributes $15,000 to their 401(k), they can only contribute a maximum of $8,500 to a 403(b) from a second job in the same year. The responsibility for tracking this combined limit rests with the employee, not the employers.

Workers aged 50 and over can make additional “catch-up” contributions. For 2025, this standard catch-up amount is $7,500, bringing their potential combined total to $31,000. A provision effective in 2025 allows those aged 60, 61, 62, and 63 to make a higher catch-up contribution of $11,250, bringing their potential total to $34,750.

Separate Overall Contribution Limits Per Employer

While employee contributions are subject to a shared personal limit, a different and much higher limit applies to the total contributions made to each plan. This is the overall limit, under Internal Revenue Code Section 415(c), and it includes employee deferrals, employer matching funds, and any other employer contributions. For 2025, this overall limit is $70,000 per plan.

This cap is applied on a per-employer, not a per-individual, basis. Each employer’s plan has its own separate $70,000 overall limit. Consider an employee under age 50 who contributes $11,750 to their 401(k) at Company A and $11,750 to their 403(b) at Organization B, maxing out their $23,500 employee limit. Company A could provide a match and profit-sharing contribution, bringing the total additions to that 401(k) to $70,000. Simultaneously, Organization B could contribute to the 403(b), also bringing that plan’s total additions up to its own separate $70,000 limit.

Special 403b Catch Up Contribution Rules

Beyond the standard age-based catch-up, 403(b) plans offer a catch-up provision for long-tenured employees. This rule, the 15-year service catch-up, allows eligible participants to make additional contributions. To qualify, an employee must have completed at least 15 years of service with the same qualified employer, which includes entities like public schools, hospitals, or home health service agencies.

This special catch-up allows an additional contribution of up to $3,000 per year, with a lifetime maximum of $15,000. Eligibility also depends on an employee’s prior contribution history; their average annual contributions in previous years must not have exceeded $5,000. This 15-year rule can be used with the standard age 50+ catch-up contribution and is a feature specific to 403(b) plans.

Coordinating Contributions and Correcting Excess Amounts

Managing contributions to multiple retirement plans requires planning to avoid exceeding the shared limit. An individual with two jobs should calculate the total annual contribution they wish to make and then allocate that amount between the two plans. This involves adjusting the per-paycheck deferral percentage with each employer’s payroll department to ensure the combined total does not surpass the legal limit.

If an over-contribution occurs, the employee must notify one or both plan administrators of the excess amount. The excess contribution, along with any earnings, must be distributed back to the employee by the tax filing deadline, April 15 of the following year. When corrected on time, the distributed excess amount is treated as taxable income in the year the contribution was made. The earnings distributed are taxable in the year they are received. Failing to correct an excess contribution before the deadline results in double taxation of the excess amount.