SEP-IRA vs Solo 401(k): Which Retirement Plan Is Best for Self-Employed? (2026)

You're self-employed.

No employer 401(k). No employer match. But you still need to save for retirement.

Here's the good news: Self-employed retirement plans let you save MORE than W-2 employees—up to $69,000 per year (2026).

But which plan should you choose?

SEP-IRA or Solo 401(k)?

This guide compares both, explains contribution limits, and helps you pick the best plan for your situation.

Quick Comparison: SEP-IRA vs Solo 401(k)

What Is a SEP-IRA?

SEP-IRA (Simplified Employee Pension) = Employer-funded retirement plan for self-employed people.

How It Works:

• You (the employer) contribute up to 25% of net self-employment income
• Max contribution: $69,000 (2026)
• No employee deferral (you can't contribute from your "paycheck"—only as the employer)
• Tax-deductible: Contributions reduce your taxable income
• Tax-deferred growth: Pay taxes when you withdraw in retirement

Who It's For:

• Self-employed individuals with variable income
• Freelancers who want simplicity (minimal paperwork)
• Small business owners with employees (SEP-IRA is easy to extend to employees)

What Is a Solo 401(k)?

Solo 401(k) (Individual 401(k)) = Retirement plan for self-employed people with no employees (except spouse).

How It Works:

• You (the employee) contribute up to $23,500 (2026) as employee deferral
• You (the employer) contribute up to 25% of net self-employment income
• Max total contribution: $69,000 (2026) or $76,500 if age 50+ (catch-up)
• Tax-deductible (Traditional) OR Roth option (pay taxes now, grow tax-free)
• Loan option: Borrow up to $50,000 from your Solo 401(k)

Who It's For:

• Self-employed individuals who want to maximize contributions
• Freelancers with lower net profit (employee deferral helps)
• People who want a Roth option or loans

SEP-IRA vs Solo 401(k): Contribution Limits (2026)

SEP-IRA Contribution Formula:

Contribution = Net self-employment income × 25%

Max: $69,000

Example:

• Net profit: $100,000
• Contribution: $25,000 (25%)

If net profit is $276,000+: You hit the $69K max.

Solo 401(k) Contribution Formula:

Contribution = Employee deferral ($23,500) + Employer contribution (25% of net profit)

Max: $69,000 ($76,500 if age 50+)

Example 1 (Lower income):

• Net profit: $50,000
• Employee deferral: $23,500
• Employer contribution: $12,500 (25% of $50K)
• Total contribution: $36,000

Example 2 (Higher income):

• Net profit: $182,000
• Employee deferral: $23,500
• Employer contribution: $45,500 (25% of $182K)
• Total contribution: $69,000 (max)

SEP-IRA vs Solo 401(k): Which Lets You Contribute More?

Solo 401(k) wins for lower incomes.

Why: The $23,500 employee deferral lets you contribute more even if your net profit is low.

Example:

• Net profit: $50,000

SEP-IRA:

• Contribution: $12,500 (25%)

Solo 401(k):

• Employee deferral: $23,500
• Employer contribution: $12,500
• Total: $36,000 (nearly 3x more!)

Both are equal at higher incomes.

Breakeven point: ~$92,000 net profit

At $100K+ net profit:

• SEP-IRA: $25,000
• Solo 401(k): $23,500 + employer contribution ≈ same

At max ($276K+ net profit):

• Both hit $69,000 max

SEP-IRA vs Solo 401(k): Roth Option

SEP-IRA:

❌ No Roth option (all contributions are pre-tax)

Solo 401(k):

✅ Roth option available (employee deferral only)

Why this matters:

• Traditional (pre-tax): Deduct now, pay taxes in retirement
• Roth: Pay taxes now, grow and withdraw tax-free

Best for:

• Young self-employed people (lower tax bracket now, higher in retirement)
• High earners who want tax diversification

Note: Employer contributions are always pre-tax (can't be Roth).

SEP-IRA vs Solo 401(k): Loans

SEP-IRA:

❌ No loans allowed

Solo 401(k):

✅ Loans allowed (up to $50,000 or 50% of account balance, whichever is less)

Why this matters:

• Emergency access to retirement funds (without 10% early withdrawal penalty)
• Must repay with interest (to yourself)

Downside: Borrowed money isn't invested (missed growth potential).

SEP-IRA vs Solo 401(k): Setup and Maintenance

SEP-IRA:

✅ Easy setup

• Open account with any brokerage (Vanguard, Fidelity, Schwab, etc.)
• Fill out IRS Form 5305-SEP (simple 1-page form)
• No annual filings (unless assets exceed $250K)

✅ Low maintenance

• No annual paperwork (until assets exceed $250K)

Solo 401(k):

⚠️ Moderate setup

• Open account with brokerage (Vanguard, Fidelity, E*TRADE, etc.)
• Adopt a 401(k) plan document (provided by brokerage)
• Obtain an EIN (Employer Identification Number) if you don't have one

⚠️ More maintenance

• Form 5500-EZ required once assets exceed $250K (annual filing)
• Track employee and employer contributions separately

Not a dealbreaker, but slightly more complex.

SEP-IRA vs Solo 401(k): Which Should You Choose?

Choose SEP-IRA if:

• You want simplicity (minimal paperwork)
• Your income is variable (easy to adjust contributions)
• You have employees (SEP-IRA extends easily to staff)
• You're OK with pre-tax only (no Roth)

Choose Solo 401(k) if:

• You want to maximize contributions (especially if lower income)
• You want a Roth option (tax-free growth)
• You want loan access (emergency funds without penalty)
• You're OK with slightly more paperwork

Can You Have Both?

No. You can only contribute to one employer-sponsored plan per year (SEP-IRA OR Solo 401(k), not both).

The $69,000 limit applies across ALL plans.

Exception:

• You CAN have a Solo 401(k) from self-employment AND a 401(k) from an employer job
• But combined employee deferrals can't exceed $23,500 (2026)
• Employer contributions are separate (each plan can contribute up to the limits)

How to Set Up a SEP-IRA or Solo 401(k)

SEP-IRA Setup (5 minutes):

1. Open a SEP-IRA account (Vanguard, Fidelity, Schwab, etc.)
2. Fill out Form 5305-SEP (provided by brokerage)
3. Make contributions (by tax filing deadline + extensions)

Deadline: Tax filing deadline (April 15, or October 15 with extension)

Solo 401(k) Setup (30 minutes):

1. Obtain an EIN (if you don't have one): IRS.gov/EIN
2. Open a Solo 401(k) account (Vanguard, Fidelity, E*TRADE, etc.)
3. Adopt a plan document (provided by brokerage)
4. Make contributions (by tax filing deadline + extensions)

Deadline:

• Plan must be established by December 31 of the tax year
• Contributions can be made until tax filing deadline + extensions

How Much Should You Contribute?

Max out if possible.

The more you contribute, the more you reduce taxable income and grow tax-deferred (or tax-free with Roth).

At minimum, contribute enough to:

• Reduce taxable income to a lower tax bracket
• Build emergency fund first (don't over-contribute and leave yourself cash-poor)

Calculate your contribution:

SEP-IRA: Net profit × 25%
Solo 401(k): Up to $23,500 + (Net profit × 25%)

Tax Benefits of SEP-IRA and Solo 401(k)

Immediate Tax Deduction

Contributions reduce your taxable income.

Example:

• Net profit: $100,000
• Solo 401(k) contribution: $40,000
• Taxable income: $60,000
• Tax savings: ~$8,800 (22% bracket + 15.3% SE tax)

Tax-Deferred Growth

Investments grow without annual taxes (pay taxes when you withdraw in retirement).

Roth Option (Solo 401(k) Only)

Pay taxes now, grow and withdraw tax-free.

Withdrawal Rules (SEP-IRA and Solo 401(k))

Age 59½ or Later:

Withdraw penalty-free (pay income tax on Traditional, no tax on Roth)

Before Age 59½:

• 10% early withdrawal penalty (plus income tax)
• Exceptions: First home ($10K), disability, medical expenses (>7.5% AGI), etc.

Required Minimum Distributions (RMDs):

• Must start withdrawing at age 73 (or 75 for those born 1960+)
• Applies to Traditional (not Roth)

Start Saving for Retirement Today

The best time to start was 10 years ago. The second-best time is today.

Quick start:

1. Choose SEP-IRA (simplicity) or Solo 401(k) (maximize contributions)
2. Open an account with a brokerage (Vanguard, Fidelity, Schwab)
3. Calculate your contribution (use formulas above)
4. Set up automatic contributions (monthly or lump sum)

At tax time, you'll reduce your tax bill AND build wealth for retirement.

Track business expenses to maximize deductions with CentSense →

Further Reading

• Self-Employment Tax Explained →
• 27 Tax Deductions for Freelancers →
• IRS SEP-IRA Guide
• IRS Solo 401(k) Guide