Yes, a spouse who is compensated by your business is eligible to participate in your Solo 401(k) as a plan member. A participating spouse does not disqualify the plan. In fact, including a spouse can meaningfully expand the plan's contribution capacity and consolidate family retirement savings into a single structure.
The key requirement is that your spouse must receive earned compensation from the business—not simply hold an ownership interest. Ownership alone does not make someone eligible to participate in a 401(k). How that compensation is structured depends on your business type.
In a sole proprietorship or single-member LLC taxed as a pass-through, you will need to issue your spouse W-2 wages from the business. This is the most common arrangement, even when the spouse's role in the business is limited.
In a partnership or partnership LLC where both spouses are active, each spouse receives a share of partnership income on a K-1, which qualifies as compensation for plan purposes. A qualified joint venture, available to spouses who jointly operate a business, allows both to report income on separate Schedule C returns without being treated as a formal partnership.
In a corporation, both spouses receive W-2 wages from the company, which is straightforward.
A participating spouse has their own separate account within the Solo 401(k) plan trust. Each spouse can make employee deferral contributions up to the individual annual limit based on their own compensation. Employer profit-sharing contributions must be made at the same percentage for all eligible participants based on their share of business income. You cannot contribute on a profit-sharing basis to one spouse's account but not the other's.
The result is a plan that can shelter significantly more income than a single-participant plan, while keeping both spouses' assets in one trust structure with a single set of plan documents.
Although each spouse maintains a separate account within the plan for recordkeeping and tax purposes, both accounts sit within the same Solo 401(k) trust. Investment decisions and transactions are executed from a single trust bank account, giving the combined pool of assets more flexibility and purchasing power than two separate IRA-based plans would provide.
In some cases, a spouse who is not regularly active in the business may want to roll existing retirement savings into the Solo 401(k) to gain self-directed investment access. This is permitted. The spouse joins the plan as a compensated employee, establishes their account, and completes the rollover. Once the rollover is done, employment can end. The rolled funds remain in the plan and continue to be invested, but the former employee-spouse cannot make new contributions after employment has been terminated.
Does my spouse need to work full-time in the business to participate?
No. Part-time employment is sufficient, provided your spouse receives legitimate compensation and that compensation is reported appropriately. The amount contributed is limited by the compensation received, so a spouse earning a modest wage from the business will have a lower contribution ceiling than a full-time participant.
Do employee deferral limits apply separately to each spouse?
The employee deferral limit is an individual limit. Each spouse has their own cap based on their compensation. However, if either spouse also participates in a 401(k) or similar plan with another employer, their individual deferral limit applies across all plans combined. See Can I have a Solo 401(k) if I also have a day job? for more on this.
This information is provided for educational purposes only and should not be interpreted as tax, legal, or investment advice. Readers are encouraged to consult a qualified professional who can offer guidance based on their personal situation.