Hire Your Spouse in Your S-Corp: Doubling Solo 401(k) Contributions

Most S-corp owners know the solo 401(k) caps out at $72,000 per year (2026). What most don't know: if your spouse performs genuine services for the business and you put them on payroll as a W-2 employee, they become an eligible plan participant — adding a second full set of contribution limits. A properly structured arrangement can get a couple to $130,000–$144,000+ in combined annual retirement contributions, while still maintaining solo 401(k) status and avoiding the complexity of a full employee retirement plan.

Why the spousal employment strategy works

When your spouse earns W-2 wages from your S-corp for real services performed, two things happen simultaneously:

• The business gets a deduction for the wages paid — reducing your pass-through income and, consequently, your QBI deduction calculation and estimated taxes
• Your spouse becomes a solo 401(k) participant — with the right to make employee deferrals and receive employer contributions based on their W-2 compensation

The 2026 contribution mechanics per participant:²

At a spouse W-2 of $60,000: employer contribution of $15,000 + employee deferral of $24,500 = $39,500 in additional retirement savings per year. If both spouses are age 50+, add another $8,000–$11,250 in catch-up contributions per person.

Worked example: owner + spouse at age 52

Suppose your S-corp nets $380,000. You pay yourself a reasonable salary of $130,000. Your spouse manages billing, client communications, and scheduling for roughly 15 hours per week — a legitimate role that supports market-rate pay of $60,000 annually.

Without the spouse on payroll, the owner alone could contribute $65,000 + $8,000 catch-up = $73,000. With the spouse as a participant, combined contributions reach $120,500. At a 35% marginal federal rate, the additional $47,500 in spouse contributions reduces federal tax by approximately $16,600 this year — plus 30+ years of compound growth on those dollars.

Contribution calculator: owner + spouse

The reasonable wage requirement

The IRS requires that your spouse's W-2 wages be legitimate compensation for real services performed at arm's-length market rates. This is the same standard that applies to your own S-corp reasonable salary — and the consequences of getting it wrong are similar: reclassification, payroll tax assessments, and potential penalties.

What qualifies as legitimate spousal employment:

• Administrative and operations support — billing, scheduling, bookkeeping, client communications, HR (for businesses with staff)
• Marketing and business development — content creation, social media, networking, event coordination
• Professional services within their expertise — if your spouse has relevant credentials or skills (legal, accounting, design, project management)
• Any role an unrelated employee could hold at the same wage for the same responsibilities

What the IRS will scrutinize:

• A spouse "employed" with no documented job description or work product
• A wage significantly above market rate for the stated role
• No payroll tax filings (Forms 941, W-2) despite claimed employee status
• Contributions being made without the underlying payroll documentation

Document your spouse's role the same way you would for any employee: written job description, time records, and a written employment agreement. If your spouse genuinely supports the business and you're currently paying them informally or not at all, formalizing the arrangement and the payroll is both legally appropriate and financially valuable.

Setting up the payroll

Once you've established the role and wage, the mechanics follow the same process as any S-corp owner-employee payroll — covered in detail in the S-corp payroll setup guide. Key steps:

1. Add your spouse to payroll — W-4 on file, regular paycheck cycle (biweekly or monthly)
2. File Form 941 quarterly — withhold and remit federal income tax, Social Security (6.2%), and Medicare (1.45%) on spouse wages; the employer (S-corp) matches FICA
3. Issue a W-2 by January 31 — Box 1 wages are used to calculate the 25% employer contribution and the employee deferral limit
4. Enroll spouse in the solo 401(k) — most plan documents allow for spousal participation; confirm with your plan provider that the adoption agreement covers employees who are spouses
5. Make contributions before the plan deadline — employee deferrals elected by December 31; employer contributions due by the corporate tax return due date (including extensions)

Hiring your minor child: sole proprietors and LLCs only

A separate but related strategy applies to sole proprietors and single-member LLCs (disregarded entities): wages paid to a child under age 18 who works in the family business are exempt from Social Security and Medicare taxes under IRC §3121(b)(3)(A), and exempt from FUTA under IRC §3306(c)(5).³

The tax benefit:

• Your business deducts the wages at your marginal rate
• Your child pays no FICA on those wages
• Your child's 2026 standard deduction (limited, as a dependent) shelters approximately the first $15,000–$16,000 of earned income from federal income tax
• Result: up to ~$15,000 in wages shifts from your 32–37% bracket to $0 effective rate for the child

Requirements for the child employment strategy:

1. Real work at reasonable wages — a 10-year-old can't be a "social media manager" at $50/hour; a 16-year-old doing administrative tasks at $15–$18/hour is defensible
2. Keep a simple time log and job description
3. Run proper payroll — W-4, regular paychecks, and a W-2 at year-end (even if no withholding is required)
4. Child's wages must be paid from your business bank account, not personal funds

Common mistakes

Hiring spouse/child with no actual work

The IRS treats wages as disguised distributions if no real services are being performed. The deduction is disallowed, payroll taxes are assessed, and penalties apply. The strategy must be built on a genuine employment relationship.

Not updating your solo 401(k) plan document

Not all prototype solo 401(k) plans automatically cover spouses. Review your adoption agreement before enrolling your spouse. Many low-cost plans (Fidelity, Schwab, E*TRADE) do cover spouses under a single-employer plan; custom plans from MySolo401k or Carry may offer cleaner documentation. If you're unsure, call your plan custodian and ask specifically: "Does my plan document cover a spouse who is a W-2 employee of the business?"

Hiring non-spouse employees and expecting solo 401(k) rules to still apply

The spousal exception is narrow. If you hire a non-spouse full-time W-2 employee (other than a part-time employee meeting the SECURE 2.0 long-term part-time rules), your plan immediately becomes a regular 401(k) subject to nondiscrimination testing, minimum coverage rules, and potentially the need to offer the plan to eligible employees. See the 1099 vs. W-2 classification guide before your first non-spouse hire.

Aggregation with spouse's own plan

If your spouse also has self-employment income and maintains their own solo 401(k) or SEP IRA, those plans may need to be aggregated for contribution limit purposes depending on whether the businesses are treated as a "controlled group" under IRC §414(b)/(c). For most husband-wife businesses with truly separate operations, aggregation is not required — but get guidance from your CPA before assuming plans can be run independently.

How spousal employment stacks with other S-corp strategies

Spousal employment on S-corp payroll is one layer of a broader owner-employee tax strategy. Combined with the other tools:

• Reasonable salary optimization — calibrate your own W-2 to minimize FICA while preserving QBI W-2 wage limitations
• Accountable plan — reimburse both spouses' business expenses tax-free (vehicle, home office, phone, professional fees) — both spouses as employees qualify
• Augusta Rule (§280A(g)) — rent your home to the S-corp for up to 14 days; income excluded from both spouses' returns
• Spousal solo 401(k) (this page) — second set of contribution limits, potentially doubling tax-deferred savings
• QBI deduction — additional W-2 wages from spousal payroll can increase the W-2 wage limitation test above the phase-out threshold

At $380K business income with both spouses employed and all five strategies layered, it is realistic to shelter $120,000–$140,000 of income annually between retirement contributions, accountable plan reimbursements, Augusta Rule rental income, and the QBI deduction — at a combined effective rate that makes the cost of a specialist financial advisor and CPA negligible by comparison.