Can a business or individual adopt a separate Solo 401(k) plan for another entity or business?

One must first determine whether adopting the additional Solo 401(k) would violate the CONTROLLED GROUP RULES set up by the IRS and Department of Labor.

The Controlled Group Rules were created essentially to protect employees from a business owner or executive establishing a separate 401(k) plan for another business and thereby not offering those employees the benefits inherent in participating in a 401(k) qualified retirement plan.

The IRS and Department of Labor were concerned that business owners wanting to establish a qualified retirement plan, but not wanting the burden of having to provide benefits to all eligible employees, would create a new separate business which would have no employees other than the owner or executive and then adopt a solo 401(k) plan for that company. Since the new company would be wholly owned by the business owner and would not have any full-time employees, the business owner could establish his or her own solo 401(k) plan and, thus, enjoy all the benefits of having a qualified retirement plan without having to provide any benefit to the employees from the other company.


As per Internal Revenue Code Section 414, a controlled group is any two or more corporations connected through stock ownership in any of the following ways:

Parent-subsidiary group

Brother-sister group

Combined group


To determine whether one is part of a controlled group, one must take into account the stock attribution rules.

The purpose of the stock attribution rules is to attribute shares, or interest in a company held by certain family members, to the person in question and determine whether that person is part of a controlled group. Internal Revenue Code Section 318 governs the stock attribution rules. Pursuant to Internal Revenue Code Section 318,an individual shall be considered as owning the stock, owned directly or indirectly, by or for -

(i) his/her spouse (other than a spouse who is legally separated from the individual under a decree of divorce or separate maintenance)

(ii) his/her children, grandchildren, parents


IRS does have a procedure through which a company can request to be treated as a Separate Line of Business. (see IRC §414(r)) . Following are limitations for these requests:


No. Members of a controlled group may each have a different plan. Similarly, two or more members of the controlled group may adopt a single plan. In either case, all employees of the controlled group must be taken into account for testing purposes.

For example, if one company is owned by a shareholder with greater than 80% and has no employees, but that same person also has ownership of over 80% in another company with full-time employees, a single plan may be adopted for both companies. However, the adopted plan must provide benefits to the eligible employees from the second company.

In other words, the rules are in place to restrict the owner(s) of a business with full-time employee from establishing a new company with no employees and adopt a Solo 401(k) plan that would exclude the full-time employees from the other company. The IRS and Department of Labor wanted to make sure that all eligible employees of a company that is part of a controlled group receives all available retirement benefits.

Controlled Group Examples:

Example 1: Joe owns 90% of Company A that has 3 employees. Joe wants to adopt a qualified retirement plan, but does not want to offer any benefits to his employees. Joe decides he will establish a new company that has no employees and adopt a Solo 401(k) Plan through that new company. Before proceeding, Joe talks with a tax attorney about his idea. Joe’s tax attorney quickly points out that since Joe would own more than 80% of Company A and the newly established company, both companies would be part of a controlled group. This would prohibit Joe from establishing a plan for the new company without offering the employees from Company A the same plan benefits.

Example 2. Joe owns 45% of Company A and Joe’s son, Mike, owns the remaining 55% interest. Company A has 5 full-time employees. Joe and Mike want to establish a 401(k) plan so they make tax-deferred contributions, but don’t want to provide the employees with any plan benefits. Joe and Mike come up with the idea of forming a new company that will have no employees other than themselves and adopt a 401(k) plan through the new company. Joe talks this over with his tax attorney and learns that since Joe and Mike are father and son, under Internal Revenue Code Section 318 they will be treated as owning each other’s shares, giving them each over 80% interest in Company A and, thus, triggering the controlled group rules. Hence, Joe and Mike would be limited from opening a 401(k) plan for the new business and not offering plan benefits to the employees from Company A. Joe and Mike could establish a plan for the new company, but the controlled group rules would require that the plan benefits be provided to all eligible employees from both companies.

Example 3. Joe owns 78% of Company A and Tim, his friend, owns the remaining 22%. Company A has 12 full-time employees. Company A does not have a 401(k) Plan. Tim does some consulting on a part-time basis and wants to establish a new corporation for his consulting business as well as establish a Solo 401(k) plan. Tim speaks with his tax attorney to inquire whether he could adopt a Solo 401(k) plan for his new business without being required to offer benefits to the 12 full-time employees with Company A. Tim’s tax attorney told Tim that because he owns less than 80% of Company A, his new consulting company would not be part of a controlled group and, thus, he would not be required to offer 401(k) benefits from his new company to the Company A employees.

Example 4. Joe and Tim each own 50% of Company A, which has 4 full-time employees. Company A currently offers its employees 401(k) plan benefits. Joe and Tim are each over the age of 59 ½ and are interested in using some of their retirement funds to purchase real estate. Unfortunately, Company A’s retirement plan does not allow for non-traditional investments, such as real estate. Joe and Tim decide to establish a new corporation, which they will each own 50% of and then have that new company adopt a new 401(k) plan. Before proceeding, Joe and Tim decided to speak with their tax attorney to make sure this strategy would work. Joe and Tim’s tax attorney advised them that as the new company will be owned by the both of them, just like Company A, the controlled group rules would be triggered since the same five or fewer individuals own at least 80% of the stock of the two corporations. Thus, Jim and Tim would not be able to adopt a new 401(k) plan without offering the same benefits to the employees from Company A.

To learn more about how the controlled group rules as they apply to the establishment of a Solo 401(k) plan, please contact a tax expert at 800-472-0646.

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