SEP-IRA vs. Solo 401(k) vs. SIMPLE IRA: Which Self-Employed Retirement Plan Actually Fits You?

Educational guide — retirement savings options that go far beyond a standard IRA's $7,500 limit

A standard IRA caps out at $7,500 a year for 2026 ($8,600 if you're 50 or older). If you're self-employed or run a small business, that's often just the starting point — SEP-IRAs, Solo 401(k)s, and SIMPLE IRAs can allow dramatically higher contributions. Here's how the three actually compare.

SEP-IRA: Simple, But Capped by a Percentage

A Simplified Employee Pension (SEP) IRA is funded entirely by employer contributions — even when the "employer" is you, contributing on your own behalf as a self-employed person.

2026 limit: the lesser of 25% of compensation or $72,000, with compensation capped at $360,000 for this calculation.

Key features:

• Only the business contributes — there's no employee salary deferral component, unlike a 401(k)
• If you have employees, you generally must contribute the same percentage for every eligible employee that you contribute for yourself — you can't favor the owner
• No catch-up contribution for those 50+ (since the limit is percentage-based, not a flat employee deferral)
• Very low administrative burden — no annual filing requirement in most cases, easy to set up

The math trap people miss: you need $288,000 of net income to actually reach the $72,000 cap (since $288,000 × 25% = $72,000). Below that, you're limited by the percentage, not the dollar cap. For a self-employed sole proprietor specifically, the calculation is further adjusted for self-employment tax and the contribution itself — the effective rate works out closer to about 18.6%–20% of net earnings in practice, not a clean 25%, so a tax professional's worksheet (or software) should confirm your exact number.

Solo 401(k): Usually the Best Option If You Have No Employees

A Solo 401(k) (also called an individual or one-participant 401(k)) is designed specifically for self-employed people or business owners with no employees other than a spouse. It allows contributions in two separate buckets, both counting toward the same overall annual limit:

• Employee deferral: up to $24,500 for 2026 (the same limit as a regular 401(k)), regardless of how profitable the business is
• Employer contribution: up to 25% of compensation (calculated differently depending on entity type — see below)
• Combined 2026 limit: $72,000 (under age 50), or $80,000 (age 50+, with the $8,000 catch-up added to the employee deferral)
• Those aged 60–63 may be eligible for an even higher catch-up ($11,250 instead of $8,000) under SECURE 2.0, if the plan permits it

Why this often beats a SEP-IRA at lower income levels: the $24,500 employee deferral is available regardless of profit — you don't need hundreds of thousands in net income to get meaningful savings capacity. A consultant earning $60,000 in net self-employment income could potentially defer close to the full employee amount, something a SEP-IRA's pure percentage-of-compensation formula wouldn't allow at that income level.

How the employer contribution is calculated depends on your business structure:

• Sole proprietors and single-member LLCs — based on adjusted net earnings from self-employment
• S-corp owners — based on W-2 wages paid to the owner-employee, which ties directly back to the "reasonable salary" question covered in this site's S-corp guide — a higher reasonable salary supports a larger Solo 401(k) employer contribution, within limits

One more advantage: if a spouse also earns compensation from the business, they can participate in the same Solo 401(k) too, each subject to their own limits — effectively doubling the household's contribution capacity in the right situation.

The trade-off: more administrative complexity than a SEP-IRA — plan documents need to be adopted, and once plan assets exceed $250,000, an annual Form 5500-EZ filing is generally required.

SIMPLE IRA: Built for Small Employers With a Few Employees

A SIMPLE IRA sits in between — designed for small businesses (generally under 100 employees) that want to offer a retirement benefit without the complexity of a full 401(k).

2026 limits:

• Standard employee contribution: $17,000
• Certain "applicable" SIMPLE plans (generally smaller employers who qualify under recent law changes): up to $18,100
• Catch-up (age 50+): an additional $4,000

Key features:

• Both the employee and employer contribute — employees defer part of their own pay, and the employer is generally required to either match employee contributions dollar-for-dollar up to 3% of compensation, or make a flat 2% non-elective contribution for all eligible employees regardless of whether they contribute themselves
• Simpler and cheaper to administer than a full 401(k), but with lower contribution ceilings than either a SEP-IRA or Solo 401(k) at higher income levels
• Best suited to a small business that actually has employees (beyond just the owner and spouse) and wants to offer a benefit without 401(k)-level administrative cost

A Quick Comparison

A Note on the New Roth Catch-Up Rule

Starting in 2026, a SECURE 2.0 provision requires that catch-up contributions (age 50+) be made on a Roth (after-tax) basis for anyone whose prior-year FICA wages exceeded $150,000 — this applies to 401(k)-type plans, including Solo 401(k)s. If your plan doesn't offer a Roth contribution option and you're affected by this rule, you may lose the ability to make catch-up contributions at all until the plan is updated to allow it.

Which One Should You Actually Pick?

• Just you, no employees, moderate income: Solo 401(k) generally wins — the flat employee deferral gives you meaningful savings capacity even before the business is highly profitable.
• Just you, no employees, high and stable income: either works well; Solo 401(k) still often edges out a SEP-IRA once you account for the fixed employee deferral, but a SEP-IRA's simplicity has real value if you don't want to deal with plan documents or potential Form 5500-EZ filing.
• You have several employees and want to offer a retirement benefit without heavy administrative cost: SIMPLE IRA is usually the practical choice.
• You have employees and want to maximize your own contributions regardless of what you offer employees: this gets more complex — a SEP-IRA requires equal treatment across eligible employees, which can get expensive once you have several people on payroll; a full traditional 401(k) plan (beyond the "solo" version) may be worth exploring instead.

This article is for general educational purposes only and does not constitute tax, legal, or financial advice. Retirement plan contribution calculations, especially for the self-employed, involve compensation adjustments that are easy to miscalculate. Consult a qualified CPA or financial advisor to determine your exact contribution limit and the right plan for your situation.

Tax Code References

• IRC §408(k) — Governs Simplified Employee Pension (SEP) plans, including the 25%-of-compensation/dollar-cap contribution formula and the requirement to contribute a uniform percentage for all eligible employees.
• IRC §401(k) and §415(c) — Govern 401(k) plans generally, including Solo/one-participant 401(k)s, and the overall annual additions limit combining employee deferrals and employer contributions.
• IRC §408(p) — Governs SIMPLE IRA plans, including employee deferral limits and required employer matching or non-elective contribution formulas.
• IRS Notice 2025-67 — Sets 2026 cost-of-living adjustments for SEP-IRA, Solo 401(k), SIMPLE IRA, and related contribution and catch-up limits.
• SECURE 2.0 Act of 2022 — Introduced the enhanced catch-up contributions for ages 60–63, the "applicable" higher SIMPLE plan limits for certain small employers, and the mandatory Roth catch-up rule for higher earners (FICA wages over $150,000 in the prior year), effective 2026.
• Form 5500-EZ — Annual filing generally required for one-participant (Solo) 401(k) plans once plan assets exceed $250,000.

Tax law changes frequently, including through annual inflation adjustments and new legislation. Figures and rules above reflect the law as of this writing (2026) and should be verified against current IRS guidance before relying on them.