One participant 401k contribution limits in 2015 are $18,000 for employees under age 50 and $24,000 for those age 50 and older. For 2014 one participant 401k contribution limits and for employer contribution limits see our article below.

- Traditional IRA Contribution Limits
- Roth IRA Contribution Limits
- SIMPLE IRA Contribution Limits
- SEP IRA Contribution Limits
- Traditional 401k Contribution Limits
- Roth 401k Contribution Limits
- One-Participant 401k Contribution Limits
- Coverdell ESA Contribution Limits
- HSA Contribution Limits

## One Participant 401k Contribution Limits

This table shows one participant 401k contribution limits for 2014 and 2015.

One participant 401ks contribution limits are the same as traditional 401k contribution limits.

Single participant 401ks have the same two kinds of contribution limits as traditional 401ks: limits on employee contributions and limits on combined contributions from employees and employers together.

For 2014, employee contribution limits for those under age 50 are $17,500. For those age 50 and up, contribution limits are $23,000 because of catch-up contributions. These are extra contributions allowed by congress to let baby boomers catch up in their savings plans.

In 2015, employees under age 50 have one participant 401k contribution limits of $18,000. Employees age 50 and older face contribution limits of $24,000.

Combined one participant 401k contribution limits for 2014 from employers and employees together are set at $52,000 for people under age 50 and $57,000 for those age 50 and older. For 2015, combined contribution limits are $53,000 for employees under age 50 and $59,000 for everyone else.

## One Participant 401ks Explained

One participant 401ks are also known as solo 401ks, solo-ks, uni-ks, and single participant 401ks. They are traditional 401k plans that cover a business owner who has no employees. They can also cover the business owner’s spouse.

Since they’re the same as traditional 401k plans, one participant 401ks have the same requirements and rules as traditional 401ks.

## Self Employed One Participant 401k Contribution Limits

The self employed have far more complex one participant 401k contribution limits. Contribution limits for the self employed are roughly 18.6% of net profit. Self employed taxpayers who contribute to a one participant 401k will find the services of a CPA helpful in figuring their contribution limits.

If an accountant isn’t an option, self employed people can use the worksheets in IRS Publication 560 to calculate their one participant 401k contribution limits.

For the self employed, the contribution limit is net profit minus half the self employment tax minus the 401k contribution. The math is circular – a participant needs to know their contribution amount to figure their contribution limit. This is why an accountant is helpful in figuring one participant 401k contribution limits.

## Other One Participant 401k Contribution Limits and Facts

- Employees must have earned income to make one participant 401k contributions.
- Contributions to one participant 401ks can’t exceed the employee’s annual income.
- Employers face additional 401k contribution limits of 25% of the employee’s income for their contributions to employee plans.

To compare retirement plans, see our articles on traditional 401k contribution limits, Roth 401k contribution limits, traditional IRA contribution limits and Roth IRA contribution limits.

**Sources**

- One Participant 401k Plans – IRS.gov
- Retirement Topics – 401(k) and Profit-Sharing Plan Contribution Limits – IRS.gov