One of the biggest advantages of working for yourself is that nobody tells you what to do with your retirement savings. One of the biggest challenges is exactly the same thing. Without an employer setting up a plan and matching your contributions, you have to build your own retirement strategy from scratch.
The good news is that the IRS gives self-employed people access to two of the most powerful retirement accounts available to anyone in the US: the SEP-IRA and the Solo 401k. Both allow you to shelter a significant amount of income from taxes each year. But they work differently, and choosing the wrong one can cost you thousands of dollars in missed contributions and unnecessary tax bills.
This guide explains how each plan works, what the 2026 limits are, and how to decide which one is the right fit for your situation.
Why Retirement Planning Matters More When You Are Self-Employed
When you work for a traditional employer, retirement savings often happen automatically. Your company offers a 401k, you set a contribution percentage, and money flows into the account before you ever see it. Many employers also match a portion of what you put in, which is essentially free money.
As a freelancer, none of that exists. No automatic contributions, no employer match, and no one reminding you to save. The entire responsibility falls on you.
There is also a tax dimension that makes this more urgent than most freelancers realize. Every dollar you contribute to a SEP-IRA or Solo 401k reduces your taxable income for the year. That means lower income tax and a smaller self-employment tax bill. Retirement contributions are not just about future savings. They are one of the most effective tax reduction tools available to you right now.
What Is a SEP-IRA?
SEP stands for Simplified Employee Pension. A SEP-IRA is an individual retirement account that self-employed people and small business owners can open and fund themselves in the role of employer.
The main appeal of a SEP-IRA is its simplicity. There is almost no administrative work involved. You open the account at any major brokerage, contribute when you want, and deduct the contribution on your tax return. There are no annual filings with the IRS, no plan documents to maintain, and no complicated setup process.
For 2026, the SEP-IRA contribution limit is the lesser of 25 percent of your net self-employment compensation or $72,000. In practice, self-employed individuals use a slightly adjusted calculation that works out to approximately 20 percent of net self-employment income rather than a straight 25 percent, due to the way the IRS accounts for the self-employment tax deduction.
One important limitation: a SEP-IRA only allows employer contributions. There is no employee contribution component. That means to reach the $72,000 maximum, you would need net self-employment income of roughly $280,000 or more. At lower income levels, the SEP-IRA caps out well below the maximum.
SEP-IRAs also do not allow catch-up contributions for people aged 50 and older, which is a meaningful disadvantage compared to the Solo 401k if you are starting to save for retirement later in your career.
What Is a Solo 401k?
A Solo 401k, also called an Individual 401k or One-Participant 401k, is a retirement plan designed specifically for self-employed individuals with no full-time employees other than a spouse.
The key difference from a SEP-IRA is that a Solo 401k has two separate contribution buckets. You contribute as both the employee and the employer, which allows you to reach much higher contribution amounts at lower income levels.
For 2026, the contribution structure works as follows.
As the employee, you can contribute up to $24,500 in salary deferrals regardless of your income level. If you are aged 50 to 59 or 64 and older, you can add a catch-up contribution of $8,000, bringing the employee deferral to $32,500. If you are between 60 and 63, SECURE 2.0 allows an enhanced catch-up of $11,250 instead, for a total employee deferral of $35,750.
As the employer, you can contribute an additional 25 percent of your net self-employment compensation on top of the employee deferral.
The combined total of employee and employer contributions cannot exceed $72,000 in 2026, or $80,000 with the standard catch-up, or $83,250 with the enhanced catch-up for ages 60 to 63.
SEP-IRA vs Solo 401k: Side by Side Comparison
| Feature | SEP-IRA | Solo 401k |
|---|---|---|
| 2026 contribution limit | Up to $72,000 | Up to $72,000 (plus catch-up) |
| Employee deferral | No | Yes, up to $24,500 |
| Employer contribution | Up to 25% of compensation | Up to 25% of compensation |
| Catch-up contributions (age 50+) | No | Yes, $8,000 or $11,250 |
| Roth option | Yes (since 2023) | Yes |
| Loan against the account | No | Yes (up to $50,000 or 50% of balance) |
| Eligible if you have employees | Yes, but you must fund them too | No, owner and spouse only |
| Administrative complexity | Very low | Moderate |
| IRS filing required | No | Yes, Form 5500-EZ when assets exceed $250,000 |
| Setup deadline | Tax filing deadline including extensions | December 31 of the plan year |
Which Plan Lets You Contribute More?
This is the question that matters most for most freelancers, and the answer depends entirely on your income level.
At lower income levels, the Solo 401k wins by a significant margin. Because it includes the employee deferral component, you can contribute up to $24,500 regardless of how much your business earned that year. With a SEP-IRA, your contribution is entirely dependent on your net income.
Here is a concrete example using a 45-year-old freelancer with $80,000 in net self-employment income in 2026.
With a SEP-IRA, the maximum contribution works out to approximately 20 percent of net income, which is $16,000.
With a Solo 401k, you contribute $24,500 as the employee plus roughly $16,000 as the employer, for a total of $40,500. That is $24,500 more in tax-deferred savings in a single year from the same income.
At higher income levels, the gap narrows. Once your net income reaches approximately $230,000 or more, both plans allow contributions near the $72,000 maximum and the difference in contribution amounts becomes negligible.
| Net Self-Employment Income | Max SEP-IRA Contribution | Max Solo 401k Contribution | Difference |
|---|---|---|---|
| $40,000 | $8,000 | $32,500 | +$24,500 |
| $80,000 | $16,000 | $40,500 | +$24,500 |
| $120,000 | $24,000 | $48,500 | +$24,500 |
| $180,000 | $36,000 | $60,500 | +$24,500 |
| $280,000+ | $70,000 | $72,000 | Similar |
When the SEP-IRA Makes More Sense
Despite the contribution advantage of the Solo 401k, there are situations where the SEP-IRA is the more practical choice.
If you have or plan to hire full-time employees, the Solo 401k is not available to you. The Solo 401k is restricted to business owners with no employees other than a spouse. A SEP-IRA allows employees, though you are required to make the same percentage contribution for all eligible employees as you make for yourself, which increases the cost significantly.
If you value simplicity above everything else, the SEP-IRA wins. There are no annual IRS filings, no plan documents, and no December 31 setup deadline to worry about. You can open and fund a SEP-IRA as late as your tax filing deadline including extensions, which means you can decide how much to contribute after you see exactly how your year turned out financially.
If your income is very high and you are already hitting the $72,000 ceiling with employer contributions alone, the additional contribution room of the Solo 401k does not matter much. At that income level, both plans become roughly equivalent in terms of how much you can put away.
When the Solo 401k Makes More Sense
For most freelancers, especially those earning under $200,000 per year, the Solo 401k offers a clear advantage.
The employee deferral is the key reason. It allows you to make a significant contribution even in a lower-income year. If your freelance business had a slow year and net profit came in around $50,000, a SEP-IRA limits you to roughly $10,000 in contributions. A Solo 401k lets you put in $24,500 as the employee plus additional employer contributions, dramatically increasing the amount you can shelter from taxes.
The Roth option is another advantage worth noting. Both plans now allow Roth contributions following changes introduced by SECURE 2.0, but the Solo 401k Roth option is more flexible and allows after-tax contributions to grow entirely tax-free in retirement.
The loan provision is also unique to the Solo 401k. If you ever need access to capital, you can borrow up to $50,000 or 50 percent of your vested balance, whichever is smaller, and repay it over time without the tax penalties that come with an early withdrawal. This is not something most freelancers plan to use, but it provides a financial safety net that the SEP-IRA does not offer.
Tax Benefits: How Both Plans Reduce Your Tax Bill Right Now
Both the SEP-IRA and the Solo 401k use pre-tax contributions by default. Every dollar you contribute comes out of your taxable income before the IRS calculates what you owe. This reduces both your federal income tax and the base on which your self-employment tax is calculated.
To see the real-world impact, consider a freelancer in the 22 percent federal tax bracket who contributes $20,000 to either plan. That contribution saves approximately $4,400 in federal income taxes in the year it is made, on top of the long-term growth the money generates inside the account.
Combined with the health insurance premium deduction and other business deductions, aggressive retirement contributions can meaningfully reduce the total tax burden for a self-employed person compared to a similarly paid employee.
Important Deadlines for 2026
The deadlines for both plans differ in ways that matter.
For a SEP-IRA, you can open the account and make contributions for 2026 as late as your tax filing deadline including extensions. If you file for an extension, that gives you until October 15, 2027 to fund your 2026 SEP-IRA. This flexibility is one of the most underappreciated features of the SEP-IRA.
For a Solo 401k, the plan itself must be established by December 31, 2026. You cannot open a Solo 401k in 2027 and retroactively count it for the 2026 tax year. Once the plan is established, you have until the tax filing deadline including extensions to make employer contributions, but employee salary deferrals must be contributed within the calendar year.
This deadline difference matters most if you are considering a Solo 401k for the first time and it is already late in the year. If you miss the December 31 setup deadline, you will need to use a SEP-IRA for that tax year and open the Solo 401k in January for the following year.
Can You Have Both a SEP-IRA and a Solo 401k?
Technically yes, but in practice it rarely makes sense to maintain both simultaneously. The IRS contribution limits apply across all plans of the same type, so having both does not let you double your contributions. The total combined contributions to both plans are still subject to the same annual limits.
The most common scenario where someone might use both is transitioning from a SEP-IRA to a Solo 401k mid-year, or maintaining a SEP-IRA for a business with employees while using a Solo 401k for a separate solo operation. If you are considering this, a CPA who specializes in self-employed clients is the right person to consult before making a decision.
Frequently Asked Questions
Do I need to make the same contribution every year? No. Both the SEP-IRA and the Solo 401k allow you to vary your contribution amount from year to year, or even skip a year entirely if your income is low. This flexibility makes both plans well-suited to the variable income reality of freelancing.
What happens to my Solo 401k if I hire an employee? If you hire a full-time employee who works more than 1,000 hours per year and is not your spouse, you generally can no longer contribute to a Solo 401k. At that point you would need to either terminate the plan and roll the funds into an IRA or a different plan type, or convert it to a standard 401k that covers employees. This is a significant administrative change, so it is worth planning ahead if you anticipate hiring.
Can I roll an existing IRA or 401k from a previous employer into these plans? Yes. Both the SEP-IRA and the Solo 401k accept rollovers from traditional IRAs and from previous employer 401k plans. This can be a smart move if you have old retirement accounts sitting elsewhere that you want to consolidate and actively manage.
Is the Roth version of these plans worth it? Roth contributions go in after tax, meaning you do not get the immediate deduction. But all future growth and qualified withdrawals are completely tax-free. The Roth option makes the most sense if you expect to be in a higher tax bracket in retirement than you are today, or if you want tax diversification across your retirement accounts. If your current income puts you in a high bracket, the traditional pre-tax approach usually wins in the short term.
Which Plan Should You Choose?
For most freelancers earning under $200,000 per year, the Solo 401k is the stronger choice. The employee deferral gives you more contribution room at lower income levels, the catch-up provisions are more generous, and the Roth and loan options add meaningful flexibility that the SEP-IRA simply does not offer.
If you value simplicity, plan to hire employees, or want the ability to decide your contribution amount as late as October of the following year, the SEP-IRA is the better fit. It requires almost no administrative effort and can be opened and funded in a single afternoon.
If you are unsure which plan makes the most financial sense for your specific income level and tax situation, a CPA who works with self-employed clients can model out the exact contribution difference and tax impact for both options before you decide. That conversation is almost always worth the cost. For context on all the ways freelancers can reduce their tax burden, see our complete guide on freelancer tax deductions.
Disclaimer: This article is for informational and educational purposes only. It does not constitute financial, tax, or legal advice. Retirement plan rules, contribution limits, and tax implications vary by individual circumstances and are subject to change. Always consult a qualified financial advisor or CPA before making retirement planning decisions.