Three retirement accounts, three very different contribution limits and paperwork burdens. Here's how to pick the right one if you work for yourself in 2026.
When you work for yourself, nobody hands you a retirement plan on your first day. There's no HR department automatically enrolling you in a 401(k), no employer match showing up quietly every payday. You have to go find a retirement account, open it yourself, and decide how much to put into it, and the three most common options for sole proprietors all sound similar enough to blur together: the SEP-IRA, the Solo 401(k), and the SIMPLE IRA. They are not remotely the same, and picking the wrong one can mean leaving thousands of dollars in tax-advantaged savings on the table every year.
A SEP-IRA (Simplified Employee Pension) lets you, as the employer, contribute up to 25 percent of your net self-employment earnings, with a hard dollar cap that adjusts annually. It's easy to set up, has almost no ongoing paperwork, and works well if your income is variable and you want flexibility to contribute a lot in good years and little in lean ones.
A Solo 401(k), sometimes called an individual 401(k), is built for a business owner with no full-time employees other than a spouse. It lets you contribute in two ways: as the "employee" up to the standard annual deferral limit, and again as the "employer" up to 25 percent of compensation, with a combined cap that's typically higher than what a SEP-IRA allows at the same income level. Solo 401(k)s can also include a Roth option and, at some providers, a loan feature.
A SIMPLE IRA is designed for small businesses with employees, including sole proprietors who have even one or two people on payroll. Contribution limits are lower than the other two options, but the plan is simpler to administer if you do have staff, and it requires an ongoing employer contribution or match once it's in place.
At the same income level, a Solo 401(k) usually lets you save more than a SEP-IRA, because the SEP-IRA only counts the employer-style contribution while a Solo 401(k) lets you stack an employee deferral on top of it. For a freelancer or consultant with healthy net income and no employees, that stacking effect can mean tens of thousands of dollars more in tax-deferred savings capacity per year compared to a SEP-IRA at the exact same income.
The SIMPLE IRA sits at the other end of the spectrum. Its deferral limit is meaningfully lower than either of the other two accounts, which makes sense given it's built for businesses that already have payroll obligations to employees. If you're truly solo with no staff, a SIMPLE IRA is rarely the best choice purely on the contribution-limit math.
A SEP-IRA is the easiest of the three to set up and maintain. Most brokerages let you open one online in minutes with a single form, and there's no annual filing requirement with the IRS as long as your plan stays under a certain asset threshold. A Solo 401(k) requires a plan document when you set it up, and once your account balance crosses $250,000, you'll need to file a short annual form (Form 5500-EZ) with the IRS. It's not difficult, but it's a step SEP-IRA owners never have to think about.
A SIMPLE IRA requires the most ongoing commitment of the three if you have employees, since you're on the hook for either a matching contribution or a fixed contribution to every eligible employee's account every year, whether or not the business had a great year.
This is where a lot of solo business owners get caught off guard. If you set up a SEP-IRA and later hire employees, you generally have to offer them the same percentage contribution you give yourself, which can get expensive fast. A Solo 401(k) technically stops being a "solo" plan the moment you have employees who qualify, and you'd need to convert it to a standard 401(k) with all the compliance testing that comes with it. A SIMPLE IRA is actually built to handle this transition most gracefully, since it was designed with small teams in mind from the start.
If you expect to hire in the next year or two, it's worth thinking that far ahead now rather than untangling it later. If you're planning to stay solo indefinitely, this consideration matters much less.
As of 2026, more providers offer a Roth version of the Solo 401(k), letting you pay taxes now in exchange for tax-free withdrawals in retirement, which can be appealing if you expect your tax rate to rise later or you're in a low-income year now. SEP-IRAs traditionally didn't offer a Roth option, though that's started to shift at some providers following recent legislation, so it's worth double-checking directly with whichever brokerage you're considering. SIMPLE IRAs have also started to gain Roth versions at select providers, but availability is still spottier than with the other two.
Take Devon, a freelance graphic designer who nets about $80,000 a year after business expenses, and Renata, a solo marketing consultant who nets closer to $140,000. Devon opens a SEP-IRA and contributes 20 percent of net earnings, landing around $16,000 for the year. If Devon had opened a Solo 401(k) instead, the employee deferral alone could add another meaningful chunk on top of a similar employer contribution, potentially pushing total contributions well above what the SEP-IRA allowed at the same income.
Renata, with higher income, opens a Solo 401(k) from the start. She maxes out her employee deferral early in the year through automatic monthly contributions, then adds an employer contribution near year-end once she knows her final net income. Between the two pieces, she's able to shelter significantly more of her income than a SEP-IRA would have allowed her at the same earnings level, all while keeping the paperwork to one short annual IRS form.
A frequent mistake is opening a SEP-IRA out of habit or because it's the first option a brokerage suggests, without ever comparing the contribution math against a Solo 401(k). Another is forgetting the Solo 401(k) deadline structure: the employee deferral portion generally needs to be elected before year-end, even though you can fund the actual contribution later, so waiting until tax time to think about it can mean missing out entirely for that year. A third common mistake is not revisiting the plan when your business changes, whether that's hiring your first employee, taking on a business partner, or seeing a big jump in net income that suddenly makes a different account far more advantageous.
Figure out your expected net self-employment income for the year as a starting point, since all three plans size their limits around that number. Compare the maximum contribution each account would actually allow you at that income level rather than relying on a general reputation for being "the generous one." Confirm whether you plan to hire employees in the near future, since that alone can rule out a couple of these options. Open the account well before year-end if you're leaning toward a Solo 401(k), since the employee deferral election typically has to happen before December 31. Finally, revisit your choice every year or two as your income and business structure evolve.
For a true solo operator with strong and growing income, a Solo 401(k) usually wins on pure contribution capacity. For simplicity and minimal paperwork, a SEP-IRA is hard to beat. For anyone who already has or plans to bring on employees, a SIMPLE IRA is often the most realistic long-term fit. None of these is a bad choice, but the size of the gap between them, in real dollars saved every year, is large enough that it's worth the hour of comparison before you pick one.
This article is for informational purposes only and does not constitute financial, tax, or investment advice. Contribution limits and rules for retirement accounts change over time; consult a qualified tax professional or financial advisor before opening or contributing to any retirement account.
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