Data Notice: Tax figures in this article reflect 2026 IRS contribution limits. Retirement plan limits are adjusted annually for inflation. Confirm current limits at IRS.gov. [sep-ira-vs-solo-401k-freelancers]

SEP IRA vs Solo 401(k) for Freelancers

Tax information in this article is for educational purposes only and does not constitute tax, legal, or financial advice. Tax laws change frequently, and individual circumstances vary. Consult a qualified tax professional or CPA for guidance specific to your situation.

For freelancers, choosing between a SEP IRA and a Solo 401(k) is one of the most impactful tax and retirement decisions you will make. Both accounts allow you to contribute far more than a traditional IRA, and both reduce your taxable income dollar-for-dollar. But they differ in contribution structures, flexibility, and features that matter at different income levels.

Side-by-Side Comparison

Feature	SEP IRA	Solo 401(k)
2026 max contribution	$72,000	$72,000 (employee + employer)
Employee elective deferral	Not available	$24,500 ($32,000 if 50+; $35,750 ages 60–63)
Employer contribution	Up to 25% of net SE income	Up to 25% of net SE income
Roth option	No	Yes
Loan provision	No	Yes (up to $50,000)
Catch-up contribution (50+)	No	$7,500 additional
Super catch-up (ages 60–63)	No	$11,250 additional
Setup deadline	Tax filing deadline (incl. extensions)	December 31 of the tax year
Contribution deadline	Tax filing deadline (incl. extensions)	Employee: Dec 31; Employer: filing deadline
Employees allowed	Yes (must cover all eligible)	No (you + spouse only)
Administrative burden	Minimal	Annual Form 5500-EZ if assets exceed $250,000

How Contributions Work

SEP IRA Contributions

SEP IRA allows only employer contributions — up to 25% of your net self-employment income (after the deduction for half of SE tax), capped at $72,000 in 2026.

Contribution formula for sole proprietors:

Start with net Schedule C profit
Subtract half of SE tax
Multiply by the effective rate (approximately 20% for sole proprietors due to the circular calculation)

Example at $100,000 net SE income:

Half of SE tax: ~$7,065
Adjusted income: $92,935
SEP contribution (20% effective): $18,587

Solo 401(k) Contributions

Solo 401(k) has two components:

Employee elective deferral: Up to $24,500 (2026), or $32,000 if age 50+, or $35,750 if ages 60–63
Employer profit-sharing: Up to 25% of net SE income (same calculation as SEP)

Example at $100,000 net SE income:

Employee deferral: $24,500
Employer contribution (20% effective): $18,587
Total Solo 401(k): $43,087

Compare this to the SEP IRA maximum at the same income: $18,587. The Solo 401(k) lets you contribute $24,500 more.

Contribution Comparison by Income Level

Net SE Income	SEP IRA Max	Solo 401(k) Max	Difference
$50,000	$9,294	$33,794	+$24,500
$75,000	$13,940	$38,440	+$24,500
$100,000	$18,587	$43,087	+$24,500
$150,000	$27,881	$52,381	+$24,500
$200,000	$37,174	$61,674	+$24,500
$290,000+	$72,000	$72,000	$0

Key insight: The Solo 401(k) advantage is exactly the employee deferral amount ($24,500) until income is high enough that the SEP IRA alone hits the $72,000 cap (around $290,000+). Below that income level, the Solo 401(k) always allows higher contributions.

When to Choose SEP IRA

Choose a SEP IRA if:

You have employees — SEP IRAs can cover employees (you must contribute the same percentage for all eligible employees). Solo 401(k) plans cannot include non-spouse employees.
You want maximum simplicity — No annual filing requirements, no plan document to maintain, setup takes minutes at any brokerage.
Your income exceeds $290,000 — At this level, both plans reach the $72,000 cap, so the SEP’s simplicity wins.
You are setting up late — SEP IRA can be established and funded up to the tax filing deadline (including extensions). A Solo 401(k) must be established by December 31.

When to Choose Solo 401(k)

Choose a Solo 401(k) if:

You earn under $290,000 — The employee deferral lets you contribute significantly more than a SEP IRA at the same income level.
You want a Roth option — Solo 401(k) plans can include a designated Roth account, allowing after-tax contributions that grow tax-free. SEP IRAs are always pre-tax.
You want loan access — Solo 401(k) plans can allow loans up to $50,000 or 50% of the vested balance. SEP IRAs do not allow loans.
You have no employees — Solo 401(k) plans are limited to business owners and their spouses.
You are over 50 — The catch-up contribution ($7,500 in 2026) increases the advantage further.

Roth Solo 401(k): The Tax-Free Growth Option

One of the Solo 401(k)‘s biggest advantages is the Roth option. You can designate some or all of your employee deferrals as Roth contributions:

Contributions are made with after-tax dollars (no immediate deduction)
Growth and withdrawals in retirement are tax-free
No income limits (unlike Roth IRA, which phases out at higher incomes)
Employer contributions are always pre-tax

This is particularly valuable if you expect to be in a higher tax bracket in retirement, or if you want tax diversification.

Can You Have Both?

Yes, but with coordination:

The $72,000 total contribution limit applies across all plans
The $24,500 employee deferral limit is shared across all 401(k) plans and SIMPLE IRAs
Having both a SEP and Solo 401(k) adds complexity without usually increasing your total contribution capacity

Most freelancers choose one or the other.

Setup Process

SEP IRA

Open a SEP IRA at any brokerage (Fidelity, Schwab, Vanguard — all free)
Complete IRS Form 5305-SEP (the plan agreement)
Fund the account by your tax filing deadline
No annual reporting required

Solo 401(k)

Establish the plan by December 31 of the year you want contributions to apply
Obtain an EIN from the IRS (if you do not already have one)
Complete the plan document (provided by your brokerage)
Fund employee deferrals by December 31; employer contributions by filing deadline
File Form 5500-EZ annually if plan assets exceed $250,000

Key Takeaways

Solo 401(k) allows significantly higher contributions than SEP IRA at income levels below $290,000
The $24,500 employee deferral is the key advantage of Solo 401(k)
SEP IRA wins on simplicity and is better for freelancers with employees
Solo 401(k) offers Roth contributions and loan provisions that SEP IRA does not
Solo 401(k) must be established by December 31; SEP IRA can be established at filing time

For retirement planning strategies, see Freelance Retirement Planning: Max Your Tax Savings. For more on how these accounts fit into a broader investment and retirement strategy, see Investment Basics: Stocks, Bonds, and ETFs Guide. For the complete picture, see our Complete Guide to Freelance Taxes in 2026. Also see the existing 401(k) Contribution Limits 2026 and IRA Contribution Limits 2026.

Sources

401(k) Limit Increases to $24,500 for 2026 — Internal Revenue Service — accessed March 28, 2026
Retirement Plans for Self-Employed People — Internal Revenue Service — accessed March 28, 2026
SEP Contribution Limits — Internal Revenue Service — accessed March 28, 2026
One Participant 401(k) Plans — Internal Revenue Service — accessed March 28, 2026