What is better for self-employed, Solo 401(k) or SEP IRA?

A Solo 401(k) is better for most owner-only businesses because it allows higher contributions at the same income. You can save as both employee and employer. A SEP IRA is better if you have employees or want the simplest plan with a late setup deadline.

How much can I contribute to a Solo 401(k) in 2026?

In 2026, you can defer $24,500 as employee, plus a $7,500 catch-up if age 50 or older. With employer profit sharing, the total limit is $71,000, or $78,500 if age 50 or older. Total limits include both pre-tax and Roth dollars, but employer dollars are pre-tax in most plans.

How much can I contribute to a SEP IRA in 2026?

In 2026, you can contribute up to 25% of compensation, up to $71,000. For sole proprietors, the effective rate is about 20% of net adjusted income after self-employment tax. There is no catch-up contribution for SEP IRAs, even if you are over age 50.

Can I have both a Solo 401(k) and a SEP IRA?

Yes, you can have both, but you rarely need both. Total employer contributions across both plans for the same business cannot exceed IRS limits. Most solo owners pick the Solo 401(k) alone for higher limits and Roth access. Ask a tax pro before funding both in one year.

Can I open a Solo 401(k) if I have a full-time job plus a side business?

Yes, if your side business has no full-time employees. Your employee deferral limit of $24,500 in 2026 applies across all 401(k) plans combined. You cannot double up on deferrals. Employer profit sharing from your side business is separate and still allowed.

Is a SEP IRA tax deductible for self-employed workers?

Yes. SEP IRA contributions are tax deductible as a business expense in the year you claim them. They lower your income tax, though not your Social Security and Medicare tax base in most cases. Growth is tax-deferred until you withdraw in retirement.

When is the deadline to open a Solo 401(k) vs SEP IRA for 2026?

Open and sign a Solo 401(k) by December 31, 2026 to count employee deferrals for 2026. You can fund employer dollars into 2027 until your tax deadline. Open and fund a SEP IRA any time until your tax filing deadline plus extension, around October 15, 2027.

Solo 401(k) vs SEP IRA: 2026 Guide | One Percent Finance

Last Updated: September 8, 2026

Solo 401(k) vs SEP IRA: Which Is Better for Self-Employed? Only 13% of self-employed workers participate in a workplace retirement plan. That is according to the U.S. Census Bureau Current Population Survey in 2023. Employees at large firms have 401(k) plans by default. Self-employed workers do not. If you freelance, run a small business, or work as an independent contractor, you must build your own plan. The two most popular options are Solo 401(k) vs SEP IRA. Both offer large tax breaks. Both allow high contribution limits for 2026. But they work in very different ways. This guide breaks down Solo 401(k) vs SEP IRA side by side. You will learn 2026 contribution limits, tax rules, costs, deadlines, and real examples. By the end, you will know which plan fits your income, age, and business goals. > Solo 401(k) vs SEP IRA Definition: A Solo 401(k) is a 401(k) plan

for a self-employed person with no full-time employees that allows contributions as both employee and employer. A SEP IRA is a Simplified Employee Pension IRA that allows employer-only contributions of up to 25% of compensation. The Solo 401(k) usually allows larger contributions at the same income level, especially for lower and middle earners. Solo 401(k) vs SEP IRA at a Glance Both plans help self-employed workers save for retirement and lower taxes. But the structure, limits, and flexibility are not the same. Here is the fast overview before we go deep. Who Each Plan Is Designed For The Solo 401(k) is built for owner-only businesses. That includes sole proprietors, single-member LLCs, freelancers, and partnerships where only owners and spouses work in the business. You cannot have full-time W-2 employees other than your spouse. The SEP IRA is more flexible on staffing. It is built for self-employed people and small employers

with a few employees. You can cover yourself and your eligible workers under one simple plan. According to the IRS in 2026, you must cover employees who are age 21 or older, earned at least $750 in 2025, and worked for you in three of the last five years. Owner-only business — a business with no full-time employees except the owner and a spouse. This is the core test for Solo 401(k) eligibility. If you are solo now but plan to hire soon, that matters. A Solo 401(k) forces you to switch plans once you hire full-time staff. A SEP IRA lets you keep the same plan and add workers. Side-by-Side Comparison for 2026 This table shows the key differences for the 2026 tax year. Limits reflect IRS cost-of-living adjustments announced in October 2025. | Feature | Solo 401(k) | SEP IRA | | --| --| --| | Who can

| December 31, 2026 to make employee deferrals | Tax filing deadline plus extension, around October 15, 2027 | | Annual filing | Form 5500-EZ once assets exceed $250,000 | No annual IRS filing | Note: For ages 60-63, SECURE 2.0 allows a super catch-up of $11,250 in 2025 and inflation-adjusted ~$11,625 expected for 2026 per IRS, for total employee deferral of ~$35,750-$36,125 and total limit of ~$82,250. The $78,500 total above applies to age 50+ excluding the 60-63 super group. For most solo earners under $150,000, the Solo 401(k) wins on contribution power. For employers with staff or those who want zero paperwork, the SEP IRA wins on ease. Learn more in our hub guide to retirement plans for self-employed workers. How Solo 401(k) Contribution Limits Work in 2026 A Solo 401(k) lets you contribute in two roles. You act as the employee and as the employer. That dual