The IRS defines a 401(k) plan as a one-participant plan that may also be referred to as a Solo-K, Uni-K or a One Participant K. Many people have incorrectly assumed that 401(k) plans can only occur in an employer-employee relationship with multiple participants in the plan. However, the IRS states the following:
“The one-participant 401(k) plan isn’t a new type of 401(k) plan. It’s a traditional 401(k) plan covering a business owner with no employees, or that person and his or her spouse. These plans have the same rules and requirements as any other 401(k) plan.”
The key element is that an individual 401(k) plan is a 401(k) plan in the eyes of the IRS. While it is a 401(k) plan, the administration and reporting requirements of an individual 401(k) plan is much simpler than that of the 401(k) plan with multiple participants.