Solo 401(k) is a traditional 401(k) plan has the same rules and regulations to be followed as other general 401(k). The small business owners with no full-time employees, their spouses and self-employed individuals are eligible to save money for retirement in this plan. It is the only plan to have two contributions and one can contribute to both contributions. The sum of the two contributions is considered as the total contribution. This total contribution does not include catch up contribution. For additional details about solo 401(k) contribution, visit their website at https://sproutira.com/