Solo 401(k) vs. SEP: Which is Best for Biz Owners?

Small business owners have several options to choose from when it comes to retirement planning. Traditional or Roth IRAs can provide a good start to saving for retirement, but successful business owners often need a plan that allows them to defer much larger amounts on an annual basis. SEP-IRAs were introduced as a way to allow small business owners to establish a retirement account for their businesses without the headaches that come with ERISA-sponsored plans. But subsequent financial legislation created the Solo 401(k), which also offers a simplified way for business owners to save for retirement and enjoy some of the benefits of a 401(k) plan that are not available with SEPs. But which type of account is better?

How They Work

SEP-IRAs have been around for decades, and they are probably still the simplest way for business owners to save for retirement. These plans are purely profit-sharing in nature and allow the owner to make contributions for himself and all eligible employees. The amount that can be contributed is the lesser of up to 25% of business revenue (20% in the case of a sole proprietorship of single member LLC) or $53,000 for 2015 and 2016. One of the main advantages of SEPs is their relative simplicity compared to the rigorous reporting requirements that come with qualified plans, even those that are designed for self-employed persons such as Keogh plans. (For more, see: Retirement Plan Options for Small-Business Owners.)

Solo 401(k) plans are a relatively recent addition to the retirement plan community. These plans are designed exclusively for sole proprietorships that have only one employee (the owner). Also known as individual or self-employed 401(k) plans, this type of retirement savings account is generally considered to be a better option for solo practitioners than SEP-IRAs because they also offer the following features:

  • Employee deferrals – Unlike SEP plans, Solo 401(k)s allow participants to make a separate employee contribution as well as a profit-sharing contribution. This allows the proprietor contribute up to $18,000 into the plan for 2015 and 2016 even if the business loses money in those years. (For more, see: Do Small Business Owners Need Financial Advisors?)
  • Catch-up contributions - Solo 401(k)s allow the same amount to be contributed by the owner as the SEP (see limits above), but they also allow participants who are age 50 and above to contribution an additional $6,000 in 2015 and 2016 as catch-up contributions. This means that the maximum dollar amount that can be saved in this plan by a business owner who is 50 or older is $59,000 for these years ($6,000 catch-up + $18,000 employee contribution + $25,000 profit-sharing contribution.)
  • Roth contributions – Solo 401(k) plans allow for Roth contributions, which can allow the owner to accumulate a substantial pool of tax-free money over time. SEP-IRAs only allow traditional pretax contributions.
  • Loan provision – Solo 401(k) plans can allow participants to take out a loan equal to the lesser of 50% of the plan balance or $50,000. Loans are not available with SEP plans. (For more, see: Independent 401(k): A Top Retirement Plan for Sole Proprietors.)

However, SEP IRAs do allow employers to make retirement plan contributions on behalf of employees, although they are allowed to exclude part-time workers, those under age 21 and those who have not worked for the employer in at least two of the last five years. Contribution limits are the same as for the owner, except that it is the lesser of the dollar limit or 25% of the employee’s total compensation. SEP-IRAs can also be established at any time before the business owner files a tax return, while solo 401(k) contributions must be made by Dec. 31 of the previous year in order to be counted on the return.

The Bottom Line

Owners of small businesses have more choices today when it comes to saving for retirement. Those who have full-time employees can save for retirement using a SEP-IRA, while solo practitioners can choose between that and a solo 401(k) plan that has higher contribution limits and other advantages. For more information on retirement plans and accounts, download Publications 575 and 590 from the IRS website or consult your financial advisor. (For more, see: Business Owners: Rules for Qualified Retirement Plans.)