SEP IRA vs Solo 401k: Best for Self-Employed in 2026

Sarah is a freelance graphic designer who made $80,000 last year. She's been self-employed for three years, and every tax season she watches a huge chunk of her income disappear to taxes. Her accountant mentioned she should open a retirement plan — something that could cut her tax bill AND help her save for the future. But when Sarah started researching, she got lost in the alphabet soup: SEP IRA, Solo 401k, SIMPLE IRA, Traditional IRA, Roth IRA... which one actually makes sense?

If you're self-employed — whether you're a freelancer, contractor, consultant, gig worker, or small business owner — you've probably hit the same wall. You want to reduce your tax bill. You want to save for retirement. But the options are confusing, and the wrong choice could mean leaving thousands of dollars on the table every single year.

Two plans dominate the conversation for self-employed workers: the SEP IRA and the Solo 401k. Both offer serious tax benefits. Both let you contribute far more than a regular IRA. But they work very differently, and the "best" one depends entirely on your situation.

In this guide, I'll break down the SEP IRA contribution limits for 2026, explain how a Solo 401k works, compare them side by side, and show you real numbers at different income levels so you can make the right call. Let's dive in.

What Is a SEP IRA?

SEP stands for Simplified Employee Pension. Despite the fancy name, it's actually one of the simplest retirement plans available for self-employed people and small business owners.

A SEP IRA works like this: you (the employer) contribute to a traditional IRA set up in your name (the employee's). There's no employee contribution — the employer puts in all the money. And since you're self-employed, you're both the employer AND the employee.

SEP IRA Contribution Limits for 2026

For 2026, the SEP IRA contribution limit is 25% of your net self-employment income, up to a maximum of $69,000.

But here's the catch that trips people up: "net self-employment income" isn't your gross revenue. It's your profit after expenses, minus half of your self-employment tax, and further reduced by the SEP contribution itself. The actual formula is a bit circular, which is why the effective contribution rate works out to roughly 20% of your net profit (after the SE tax deduction), not 25%.

Let me show you the math. Say your Schedule C net profit is $80,000:

1. Subtract half of SE tax: $80,000 − $5,652 = $74,348 (your "compensation")
2. 25% of compensation: $74,348 × 0.25 = $18,587
3. Your SEP IRA contribution: $18,587

Wait — that's only 23.2% of your original $80,000. Where'd the 25% go? The IRS formula accounts for the fact that the contribution itself reduces your compensation. It's a chicken-and-egg problem that the IRS resolves with a specific calculation. Our self-employment tax calculator handles this automatically if you want exact numbers.

Who Can Open a SEP IRA?

• Self-employed individuals (freelancers, contractors, sole proprietors, LLC owners)
• Small business owners with employees
• Anyone with earned income from self-employment, even if you also have a W-2 job
• You can set one up even if you're a side hustler with a full-time job

Key SEP IRA Features

Tax deduction: Every dollar you contribute to a SEP IRA is tax-deductible. That means a $10,000 contribution reduces your taxable income by $10,000. If you're in the 22% federal bracket, that's $2,200 less in federal taxes alone.

Deadline: You can open and fund a SEP IRA up until the tax filing deadline, including extensions. That means you could open one as late as October 15, 2027 for the 2026 tax year (if you file an extension). This is a huge advantage if you're a procrastinator — or if you want to see your full-year numbers before deciding how much to contribute.

No catch-up contributions: Unlike some other plans, SEP IRAs don't offer extra contributions for people 50 and older. The limit is the limit, period.

Employer-only contributions: The business makes all contributions. There's no "employee deferral" like you'd find in a 401k. This is important because it limits how much you can contribute at lower income levels.

Employee coverage requirement: If you have employees, you generally must contribute to SEP IRAs for all eligible employees at the same percentage rate you contribute for yourself. This can get expensive quickly.

Tax-deferred growth: Investments grow tax-deferred inside the SEP IRA. You pay taxes when you withdraw in retirement.

What Is a Solo 401k?

A Solo 401k — also called an Individual 401k or One-Participant 401k — is designed specifically for self-employed people with no employees (other than a spouse). It lets you wear two hats: you're both the employer AND the employee, and you can contribute in both capacities.

This dual-contribution structure is what makes the Solo 401k so powerful, especially at lower and middle income levels.

Solo 401k Contribution Limits for 2026

For 2026, the Solo 401k contribution limit is up to $69,000 total — but you get there through two separate channels:

1. Employee contribution (elective deferral): Up to $23,000 of your compensation. This is money you choose to defer from your pay into the 401k.
2. Catch-up contribution (age 50+): An additional $7,500 on top of the $23,000 employee deferral, bringing the employee side to $30,500 if you're 50 or older.
3. Employer contribution: Up to 25% of your compensation (same calculation as SEP IRA).
4. Total maximum: $69,000 for 2026 (or $76,500 if you're 50+ with catch-up).

The magic of the Solo 401k is that the employee contribution doesn't depend on a percentage of income. It's a flat dollar amount — $23,000 — as long as you earn at least that much. So even if your net SE income is relatively modest, you can still stash away a significant amount.

Key Solo 401k Features

Roth option: Most Solo 401k plans allow a designated Roth account. This means you can make after-tax contributions that grow tax-free and can be withdrawn tax-free in retirement. With a SEP IRA, there's no Roth option — everything is pre-tax.

Loan option: Solo 401k plans can allow loans of up to $50,000 or 50% of your vested balance, whichever is less. You pay yourself back with interest. This can be a lifeline if you need access to cash without triggering early withdrawal penalties. SEP IRAs don't offer loans.

Deadline: A Solo 401k must be established by December 31 of the tax year. You can make contributions up until the tax filing deadline (including extensions), but the plan itself must exist before the year ends. This is a crucial difference from the SEP IRA.

Annual filing requirement: If your Solo 401k balance exceeds $250,000, you must file Form 5500-EZ annually. It's a relatively simple form, but it's one more thing on your to-do list. SEP IRAs have no annual filing requirements regardless of balance.

No employees allowed: You cannot have any full-time employees (working 1,000+ hours per year) other than yourself and your spouse. If you hire an employee, you'd need to convert to a regular 401k plan or switch to a SEP IRA.

Cost: Solo 401k plans typically cost $100–500 per year to maintain, depending on the provider and whether you want Roth and loan features. Some providers offer free basic plans. SEP IRAs are usually free or very low cost ($0–50/year).

SEP IRA vs Solo 401k: Side-by-Side Comparison

Let's put them head to head. Here's the complete comparison:

Contribution Examples by Income Level

This is where the rubber meets the road. The maximum contribution is the same for both plans ($69,000), but how much you can actually contribute at different income levels varies significantly. Let's run the numbers.

Note: For these calculations, I'm using net self-employment profit (Schedule C income after expenses). The Solo 401k calculations include the $23,000 employee deferral plus the employer contribution of 25% of adjusted compensation. The SEP IRA is 25% of adjusted compensation (roughly 20% of net profit).

$30,000 Net SE Income

SEP IRA:

• Adjusted compensation: ~$27,713
• 25% contribution: $6,928

Solo 401k:

• Employee deferral: $23,000 (limited to 100% of compensation, which is ~$27,713 — so full $23,000 allowed)
• Employer contribution (25% of compensation): ~$6,928
• Wait — you can't contribute more than your net earnings. The total can't exceed your net SE income.
• Actual total: $27,713 (capped at earnings)

But realistically, most providers limit employee deferrals to your net earnings. Let me simplify:

• Employee deferral: $23,000
• Employer contribution: ~$1,755 (25% of compensation after employee deferral)
• Total Solo 401k: ~$24,755

Winner: Solo 401k by a mile. At $30k income, the Solo 401k lets you contribute roughly $24,755 vs only $6,928 with a SEP IRA. That's nearly 4x more.

$50,000 Net SE Income

SEP IRA:

• Adjusted compensation: ~$46,426
• 25% contribution: $11,607

Solo 401k:

• Employee deferral: $23,000
• Employer contribution: ~$5,856
• Total Solo 401k: ~$28,856

Winner: Solo 401k again. $28,856 vs $11,607 — you can save an extra $17,249 per year.

$80,000 Net SE Income

SEP IRA:

• Adjusted compensation: ~$74,348
• 25% contribution: $18,587

Solo 401k:

• Employee deferral: $23,000
• Employer contribution: ~$12,837
• Total Solo 401k: ~$35,837

Winner: Solo 401k still. At $80k, the Solo 401k lets you put away nearly double what the SEP IRA allows.

$120,000 Net SE Income

SEP IRA:

• Adjusted compensation: ~$111,522
• 25% contribution: $27,880

Solo 401k:

• Employee deferral: $23,000
• Employer contribution: ~$22,130
• Total Solo 401k: ~$45,130

Winner: Solo 401k — but the gap is narrowing. $45,130 vs $27,880. The SEP IRA percentage-based contribution is catching up.

$200,000 Net SE Income

SEP IRA:

• Adjusted compensation: ~$185,870
• 25% contribution: $46,468

Solo 401k:

• Employee deferral: $23,000
• Employer contribution: ~$40,717
• Total Solo 401k: ~$63,717

Winner: Solo 401k — but barely. At $200k, both plans are approaching the $69,000 cap. Above roughly $280,000 in net SE income, both plans max out at $69,000 and the difference becomes negligible.

The key takeaway: If your self-employment income is under ~$280,000, the Solo 401k almost always lets you contribute more. The lower your income, the bigger the advantage. At higher incomes, the two plans converge.

When SEP IRA Wins

The Solo 401k isn't always the right choice. Here are the situations where a SEP IRA makes more sense:

You Have Employees

If your business has eligible employees (anyone 21+ who worked for you in 3 of the last 5 years and earned $750+), you must contribute to their SEP IRAs at the same rate you contribute to yours. While that sounds expensive, it's actually the reason the SEP IRA exists — it was designed for small businesses with employees.

A Solo 401k, on the other hand, can't have any employees (other than your spouse). So if you have even one full-time employee, the Solo 401k is off the table unless you want to convert to a full 401k plan (much more complex and expensive).

You Want Simplicity and Low Cost

A SEP IRA is dead simple. You fill out Form 5305-SEP (one page), open an account with any brokerage, and you're done. No annual filings. No complex administration. Maintenance costs are usually zero.

A Solo 401k requires more paperwork to set up, may have annual fees, and if your balance exceeds $250,000, you need to file Form 5500-EZ every year. For some people, that extra complexity isn't worth it.

You're a Side Hustler with W-2 Income

If you have a full-time W-2 job that already offers a 401k, and your self-employment income is from a side gig, a SEP IRA might be the cleaner option. Here's why: your 401k employee deferral limit ($23,000 for 2026) is shared across ALL 401k plans. If you're already maxing out your W-2 401k, you can't make employee deferrals into a Solo 401k too.

With a SEP IRA, there's no employee deferral — it's all employer contributions. So your W-2 401k contributions don't interfere. You can max out your workplace 401k AND contribute to a SEP IRA from your side business.

You Missed the Solo 401k Deadline

Remember, a Solo 401k must be established by December 31 of the tax year. A SEP IRA can be opened and funded up until the tax filing deadline, including extensions. If it's January and you're looking at your 2026 taxes wishing you'd set up a retirement plan — a SEP IRA can still save you. A Solo 401k for 2026? Too late.

This deadline flexibility alone makes the SEP IRA worth considering as a backup option.

When Solo 401k Wins

For many self-employed people, especially freelancers and solo consultants, the Solo 401k is the better retirement plan. Here's why:

You Want to Contribute MORE at Lower Incomes

This is the #1 reason to choose a Solo 401k. As we saw in the contribution examples, the Solo 401k's employee deferral of $23,000 means you can save dramatically more at lower and middle income levels. At $50,000 of self-employment income, a Solo 401k lets you contribute roughly $28,856 vs only $11,607 with a SEP IRA.

That's an extra $17,249 per year going into your retirement account — and an extra $17,249 deducted from your taxable income. Use our 401(k) calculator to see how that extra contribution compounds over 20 or 30 years. Spoiler: it's hundreds of thousands of dollars.

You Want a Roth Option

The Solo 401k's Roth feature is a big deal. You can split your contributions between pre-tax and Roth, giving you tax diversification in retirement. With a SEP IRA, everything is pre-tax — you'll pay ordinary income tax on every dollar you withdraw.

If you think tax rates might be higher in the future (and with the national debt where it is, that's a reasonable bet), having some Roth money gives you a tax-free bucket to draw from. This flexibility is invaluable in retirement planning.

You can also roll a SEP IRA into a Solo 401k later if you want Roth access, but that requires opening and maintaining the Solo 401k first.

You Want Loan Access

Life happens. Sometimes you need cash and you don't want to pay the 10% early withdrawal penalty. A Solo 401k lets you borrow up to $50,000 (or 50% of your vested balance, whichever is less) and pay yourself back with interest.

Is borrowing from your retirement ideal? No. But it's a lot better than taking a hardship withdrawal or racking up credit card debt at 25% interest. With a SEP IRA, there's no loan option — if you need money before 59½, you're taking a distribution and paying taxes plus the 10% penalty.

You're Over 50 and Want Catch-Up Contributions

If you're 50 or older, the Solo 401k lets you contribute an extra $7,500 as a catch-up contribution. That brings your employee deferral to $30,500 and your total possible contribution to $76,500. A SEP IRA has no catch-up provision — the $69,000 cap is the same whether you're 25 or 65.

If you're getting a late start on retirement savings (and many self-employed people are), those catch-up contributions can make a real difference.

Your Income Is Under $69,000

At incomes below roughly $69,000, the Solo 401k advantage is massive. You can potentially contribute nearly all of your net earnings, while the SEP IRA limits you to about 20%. If you're a freelancer earning $40,000 and want to save aggressively, the Solo 401k is the only plan that lets you put away a meaningful amount.

The Tax Savings Calculator: Real Numbers

Let's see the actual tax impact. We'll use Sarah, our freelance graphic designer earning $80,000 in net SE income, as an example. She's single, takes the standard deduction, and lives in a state with 5% income tax.

Without Any Retirement Plan

• Net SE income: $80,000
• Self-employment tax: ~$11,304 (15.3% × 92.35% × $80,000)
• Half of SE tax deduction: $5,652
• Adjusted gross income: ~$74,348
• Standard deduction: $15,200
• Taxable income: ~$59,148
• Federal income tax: ~$8,576
• State tax (5%): ~$3,717
• Total tax: ~$23,597

With SEP IRA ($18,587 contribution)

• SEP IRA deduction: $18,587
• New adjusted gross income: ~$55,761
• Taxable income: ~$40,561
• Federal income tax: ~$5,337
• State tax (5%): ~$2,788
• Self-employment tax: ~$11,304 (SEP doesn't reduce SE tax)
• Total tax: ~$19,429
• Tax savings: ~$4,168
• Plus $18,587 going into your retirement account

With Solo 401k ($35,837 contribution)

• Solo 401k deduction: $35,837
• New adjusted gross income: ~$38,511
• Taxable income: ~$23,311
• Federal income tax: ~$2,597
• State tax (5%): ~$1,926
• Self-employment tax: ~$11,304
• Total tax: ~$15,827
• Tax savings: ~$7,770
• Plus $35,837 going into your retirement account

The Solo 401k saves Sarah an additional $3,602 in taxes compared to the SEP IRA, AND she puts $17,250 more into her retirement account. That's a double win.

Our paycheck calculator can help you model your own numbers, and if you have investment income on top of self-employment income, check the capital gains calculator for the full picture.

Impact on Self-Employment Tax

One important note: neither a SEP IRA nor a Solo 401k reduces your self-employment tax. The 15.3% SE tax is calculated on your net earnings before any retirement contributions. Retirement deductions only reduce your income tax, not your SE tax.

The only things that reduce SE tax are business expense deductions (which reduce your net profit) and the above-the-line deduction for half of SE tax itself.

SIMPLE IRA: The Third Option

Before we wrap up, there's one more plan worth mentioning: the SIMPLE IRA. It's less common for sole proprietors, but it fills a niche.

SIMPLE IRA Contribution Limits for 2026

• Employee contribution: up to $16,000
• Catch-up contribution (50+): additional $3,500
• Employer match: dollar-for-dollar up to 3% of compensation, OR 2% nonelective contribution

When a SIMPLE IRA Makes Sense

• You have a small number of employees and want a low-cost plan
• You want both employer and employee contributions but find the Solo 401k too complex
• Your employees earn modest wages and a 2-3% match is affordable

Why It's Usually Not the Best for Solo Self-Employed

For a solo self-employed person, the SIMPLE IRA almost always allows less in total contributions than either a SEP IRA or Solo 401k. The $16,000 employee limit plus a 3% match comes out to significantly less than what you can contribute to a Solo 401k. And unlike a SEP IRA, a SIMPLE IRA requires employer contributions.

The SIMPLE IRA is best suited for very small businesses (1-10 employees) where the owner wants to offer a retirement benefit but can't afford or manage a full 401k plan.

How to Open Each Plan

Opening a SEP IRA

1. Choose a brokerage — Fidelity, Vanguard, Schwab, and E*TRADE all offer fee-free SEP IRAs
2. Fill out Form 5305-SEP — This is the plan adoption agreement. Some brokerages have their own version
3. Open the account — Usually takes 10-15 minutes online
4. Fund it — Transfer money from your bank account or business account
5. Invest — Choose your investments (index funds, target-date funds, etc.)

That's it. No IRS filing required. No annual forms. The whole process takes less than 30 minutes.

Opening a Solo 401k

1. Choose a provider — Look for one that offers Roth and loan features if you want them. Popular options include Fidelity, Vanguard, Schwab, E*TRADE, and specialized providers like Nabers Group and MySolo401k
2. Adopt the plan — You'll need to sign a plan adoption agreement and a trust document. Some providers make this simpler than others
3. Open the account — You may need both a pre-tax and a Roth sub-account
4. Get an EIN — You need an Employer Identification Number from the IRS (free, takes 5 minutes online at irs.gov) even if you have no employees
5. Fund it — Make employee deferrals and employer contributions separately
6. Invest — Choose your investments within the plan

The setup is more involved than a SEP IRA, but most providers walk you through it. Expect to spend 1-2 hours getting everything set up.

Pro tip: If you want the Roth option and loan feature, make sure your provider offers them before opening the account. Not all Solo 401k providers do — the free plans from major brokerages often lack these features.

People Also Ask

What are the SEP IRA contribution limits for 2026?

For 2026, the SEP IRA contribution limit is 25% of your net self-employment income, up to a maximum of $69,000. In practice, because of how the IRS calculates compensation, your actual contribution works out to roughly 20% of your net Schedule C profit. If you earn $100,000 in net self-employment income, you can contribute approximately $18,587 to a SEP IRA for 2026.

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

Yes, you can have both, but the total employer contribution across both plans cannot exceed 25% of your compensation, and the $69,000 annual addition limit applies across both plans combined. In most cases, it's simpler and more effective to choose one plan. Some people open a SEP IRA for years when they had employees, then roll it into a Solo 401k after closing their business to employees.

Is a Solo 401k better than a SEP IRA?

For most self-employed people without employees, yes — a Solo 401k is better than a SEP IRA. The Solo 401k allows higher contributions at most income levels, offers a Roth option, permits loans, and includes catch-up contributions for those 50+. The SEP IRA wins if you have employees, want maximum simplicity, need the flexible deadline, or are already maxing out a W-2 401k at your day job.

How much can a self-employed person contribute to a SEP IRA?

A self-employed person can contribute up to 25% of their net self-employment income to a SEP IRA, capped at $69,000 for 2026. Because of the IRS calculation method, the effective contribution rate is approximately 20% of your net profit. For example, on $80,000 of self-employment income, you could contribute about $18,587. You can contribute to a SEP IRA even if you also participate in a retirement plan through a W-2 employer.

Choosing between a SEP IRA and a Solo 401k isn't about which plan is "better" in the abstract — it's about which one is better for you. If you're a solo operator earning $50k-$150k from self-employment, the Solo 401k almost always lets you contribute more, save more on taxes, and gives you flexibility with Roth and loan options. If you have employees, value simplicity above all else, or need the extended deadline, the SEP IRA is your friend.

Either way, the most important thing is to actually open one. Too many self-employed people pay thousands in extra taxes every year because they never set up a retirement plan. Don't be one of them. Pick a plan, open it this week, and start saving. Your future self — and your tax return — will thank you.