The most common basic personal finance advice anyone gets is this—max out your 401(k) contributions. But what does that mean? How much is the maximum, and what do you do if you exceed it? And yes, you can exceed it—under certain circumstances.

For 2021, the maximum allowed contribution to a 401(k) is $19,500 per year. The combined amount contributed by employer and employee is $58,000 for 2021 ($57,000 for 2020). If you are over 50 years of age, you can make catch-up contributions of an additional $6,500 per year. Check with your human resources department to determine what kind of pace you are on.

Excess contributions are taxed at 6% per year for each year the excess amounts remain in the IRA. The tax can't be more than 6% of the combined value of all your IRAs as of the end of the tax year.

April 15 is the generally cited deadline, but the date has been moved ahead for small reasons (to skip over a holiday) and large reasons (the coronavirus epidemic in 2020).

If you live in Texas, your deadline for filing your 2020 taxes and paying any tax due has been moved to June 15, 2021, due to the snowstorm-related federal disaster declaration. If you don't live in Texas but were affected by the storm, you may still be eligible for the delayed deadline.

Key Takeaways

  • The most common basic personal finance advice anyone gets is this: max out your 401(k) contributions. But under certain circumstances, you can exceed this amount.
  • For 2021, the maximum allowed contribution to a 401(k) is $19,500 per year.
  • If you over-contributed to your 401(k) plan—that is, you contributed more than the annual maximum set by the IRS—you should notify your employer or the plan administrator immediately.

What to Do if You Over-Contributed

If you overcontributed to your 401(k) plan—that is, you contributed more than the annual maximum set by the IRS—you should notify your employer or the plan administrator immediately. Ideally, this notification should be provided by March 1 of the year after the excess deferral contribution, as it's technically known, occurred. This means that if you contributed too much in the current tax year, the notification should be provided by March 1 of the following tax year.

The excess deferral amount should be returned to you by April 15. For example, if the excess deferral occurred in the current year, it should be corrected—that is, removed from the account—by April 15 of the following year.

This sum should include earnings accrued on the excess amount while it was in your account. You are required to add the earnings to your taxable income for the year the excess amount is distributed from your 401(k).

In addition, if the excess amount was deferred on a pre-tax basis, your employer must amend your W-2 Form to show the returned amount as wages. For example, assume your excess deferral occurred this year, and you provided timely notification to your plan administrator. If your contributions were made on a pre-tax basis, your employer must amend your W-2 for this year to show the excess deferral amount as taxable wages (in Box 1).

The Excess Amount

If the excess contribution is returned to you, any earnings included in the amount returned to you should be added to your taxable income on your tax return for that year. Excess contributions are taxed at 6% per year for each year the excess amounts remain in the IRA. The tax can't be more than 6% of the combined value of all your IRAs as of the end of the tax year.

To avoid the 6% tax on excess contributions, you must withdraw:

  • Excess contributions from your IRA by the due date of your individual income tax return (including extensions)
  • Any income earned on the excess contribution

If the excess contribution is returned to you this year, for example, any earnings included in the amount returned to you should be added to your taxable income on the tax return that you file next spring.

If the excess amount is not returned to you by April 15, you could pay taxes on the amount twice—in the year the excess occurred, and in the year it is returned to you.