US self-employed

Solo 401(k) vs SEP IRA: best self-employed retirement plan 2026

By Teja Pagidimarri May 17, 2026 ~7 min read

Numbers updated... · sources

TL;DR

Solo 401(k) lets you contribute as employee ($23,500 deferral) AND employer (25% of net SE income) up to $70,000 in 2026 ($77,500 with age-50 catch-up, $81,250 with super-catch-up at 60-63). SEP IRA is simpler but employer-only, capped at 25% of compensation. Solo wins decisively below ~$200K net SE income because the employee deferral packs more in. Above $300K, both reach the same cap. Add Roth contributions, spousal accounts, and 5500 paperwork into the mix.

How each plan works

Solo 401(k) (a.k.a. Individual 401(k), one-participant 401(k)): a 401(k) for businesses with no full-time employees other than the owner (plus spouse). Contributions come in two flavors:

• Employee deferral: $23,500 in 2026 ($31,000 at 50+, $34,750 at 60-63 under SECURE 2.0 super-catch-up). Can be Roth or pre-tax. Calculated on actual W-2 wages or net SE earnings.

• Employer profit-sharing: up to 25% of net self-employment income (after self-employment tax adjustment - effectively ~20% of gross net SE income). Pre-tax only.

Combined cap: $70,000 in 2026, or $77,500 / $81,250 with catch-up.

SEP IRA (Simplified Employee Pension): IRA-based plan, employer contribution only. Up to 25% of compensation, same $70,000 cap. No employee deferral mechanism. Pre-tax only (no Roth SEP available without Roth IRA conversion).

Setup: Solo 401(k) requires a plan document and Form 5500-EZ once assets exceed $250K. SEP IRA: simple form 5305-SEP, no annual filing. SEP wins on simplicity; Solo wins on contribution flexibility.

Side-by-side at three income levels

Net SE income $80,000: • SEP IRA max: 25% of (~$74,000 after SE tax adj) = $18,500 • Solo 401(k) max: $23,500 deferral + $14,800 profit-sharing = $38,300 • Solo wins by ~$19,800

Net SE income $150,000: • SEP IRA max: 25% of $139K = $34,750 • Solo 401(k) max: $23,500 + $27,800 = $51,300 • Solo wins by ~$16,550

Net SE income $300,000: • SEP IRA max: 25% of $278K = $69,500 -> capped at $70K • Solo 401(k) max: $23,500 + $46,500 = $70,000 • Tie at the $70K cap

For most self-employed people earning under $300K, Solo 401(k) defers significantly more. The advantage shrinks to zero as income reaches the cap.

Roth contributions: a Solo 401(k) advantage

Solo 401(k) plans almost universally allow Roth on the employee deferral side. SEP IRA does not natively allow Roth.

Why this matters: a 32-year-old freelancer making $150K can put $23,500 into Roth Solo 401(k) plus $27,800 traditional profit-sharing. The Roth side grows tax-free for 35+ years - on $23.5K/year for 35 years at 7% growth = $3.25M tax-free.

SECURE 2.0 update: starting 2026, employer contributions can also be Roth (employer profit-sharing as Roth) if the plan document allows. This is brand new and many plan providers haven't updated yet.

SEP-Roth workaround: do SEP traditional, then Roth-convert via in-service rollover or annual Roth conversion. Costs current-year tax but achieves similar end state.

Spousal contributions and the 5500-EZ threshold

Spouse on Solo 401(k): if your spouse works in the business and is paid W-2 wages, both can contribute. Two $23,500 deferrals + two profit-sharing pieces = up to $140,000/year. Powerful for high-earning couples.

Spouse on SEP: only employer contributes. Same effect - 25% of spouse's comp goes in. But no deferral mechanism, so harder to maximize on lower spouse comp.

Form 5500-EZ requirement: Solo 401(k) requires annual Form 5500-EZ filing once total plan assets cross $250,000. Not difficult (one page) but a compliance step. SEP IRA never requires 5500.

Hiring an employee: hiring even one non-spouse W-2 employee disqualifies Solo 401(k) (it becomes a regular 401(k) with non-discrimination tests). SEP IRA also requires covering most employees (3 of last 5 years, $750+ comp). If you're scaling and might hire, consider this in advance.

Choosing: a 6-factor decision

1. Net SE income under $200K: Solo 401(k) wins decisively (typically $15K+ more deferral).

2. Want Roth contributions: Solo 401(k) - Roth deferral built-in.

3. Want simplest possible setup: SEP IRA - one form, no plan document, no 5500.

4. Have a working spouse to put on payroll: Solo 401(k) - lets you double up deferrals.

5. Plan to hire employees within 5 years: SEP IRA scales more cleanly (still simple, just covers them too).

6. Already maxing a W-2 401(k) elsewhere: SEP IRA - the Solo employee deferral is shared across all 401(k)s ($23,500 total). SEP profit-sharing is independent of any other 401(k).

Hybrid strategy: max your day-job 401(k) ($23,500 employee), then run a SEP IRA on side-business income for the 25% piece. Best of both worlds for tech freelancers.

Run the math for your situation

Use our US calculator to plug in your own numbers and see exactly what you owe / save.

Frequently asked questions

Quick answers people search for.

Can I have a Solo 401(k) AND a regular 401(k)?

Yes, but the $23,500 employee deferral limit is shared across both. The 25% profit-sharing piece is independent (each plan has its own $70K total cap).

What's the deadline to set up a Solo 401(k)?

Plan must be established by Dec 31 of the tax year you want it for. Contributions can be made up to the tax-filing deadline (April 15 + extensions). SEP IRA can be both established AND funded up to the tax deadline - more flexible last-minute.

Does SEP IRA reduce my Roth IRA contribution limit?

No - SEP and Roth IRA limits are independent. You can do both. SEP contributions can affect Roth eligibility indirectly via lowered MAGI but not directly.

Is a Solo 401(k) worth the 5500-EZ paperwork?

For most self-employed, yes. The 5500-EZ is one page and only required once assets hit $250K. The contribution advantage typically worth $5K-$20K/year in additional tax-deferred saving outweighs the 30 minutes of annual filing.

What is super-catch-up?

SECURE 2.0 (effective 2026) lets workers age 60-63 contribute an extra $11,250 catch-up beyond the regular $7,500. Solo 401(k) deferral cap at age 60-63: $23,500 + $11,250 = $34,750 employee piece, total cap $81,250.

Key takeaways

Age-based corpus targets: 1x income by 30, 3x by 40, 6x by 50, 8x by 60, 10-12x by retirement.
The 4% safe withdrawal rule is the practical anchor for sustainable retirement spending; 3.3-3.5% for 35+ year horizons.
Account selection matters more than fund selection - max employer match first, then prioritise tax-advantaged vehicles.
Asset allocation (stock-bond split) explains 80-90% of long-term portfolio performance; specific fund choice is the rest.
Behavioural failures (panic-selling, not starting, early withdrawals) destroy more retirement wealth than fee mistakes.
Holding a mix of Traditional + Roth + Taxable accounts gives the most retirement-year tax flexibility.

By audience: what to focus on

Different reader types need different angles on this topic. Pick the one closest to your situation.

Salaried employees

Maximise tax-advantaged retirement contributions (EPF/401(k)/SIPP/RRSP). Check whether your country prefers the old vs new regime, employer-match thresholds, and salary-sacrifice options. Use the calculators below with your CTC / gross income.

Freelancers / self-employed

You bear higher self-employment tax + lose the employer match, but get access to higher contribution limits (Solo 401k, SEP-IRA, NPS Tier-I). Track business expenses meticulously. Quarterly estimated tax payments avoid underpayment penalty.

NRIs / expats

Tax residency rules (183-day, tie-breaker), double-taxation treaties, foreign tax credits all come into play. NRI restrictions on PPF (no new accounts) but expanded options on NPS. Cross-border income often needs specialist advice.

Retirees / pre-retirees

Sequence-of-returns risk in early retirement is the largest threat. Glide-path asset allocation, Roth-conversion analysis in low-income years, Required Minimum Distribution planning, and Medicare/healthcare gap funding (US) are the big items.

Quick reference: 14 specific scenarios

Scan the question list, expand only the rows that match your situation.

How much should I have saved for retirement by my age?

Standard age-by-multiple benchmarks (Fidelity/T. Rowe Price): 1x annual income by 30, 3x by 40, 6x by 50, 8x by 60, 10-12x by 67. These targets assume a target replacement rate of 70-80% of pre-retirement income. Use our retirement calculator below to translate your actual target into a monthly savings figure.

What is the 4% safe withdrawal rule?

Originally derived from the Trinity Study, the 4% rule says you can withdraw 4% of your starting retirement balance in year 1, then adjust that dollar amount for inflation each year, and have a >95% chance of the portfolio lasting 30 years. Modern research suggests 3.3-3.5% is more defensible for longer (35-40 year) retirements or lower expected returns.

Should I prioritise Roth or Traditional retirement accounts?

Roth = pay tax now, withdraw tax-free later. Traditional = deduct now, pay tax at withdrawal. Roth wins when your retirement tax rate is HIGHER than your current rate; Traditional wins when current rate is higher. Most planners suggest holding both for tax-bracket flexibility in retirement.

Can I retire early on $1 million (10 crore)?

At the 4% rule, $1M generates $40,000/year (10 crore generates Rs 40 lakh/year). Whether that's enough depends entirely on your spending in retirement. Lean-FIRE households retire on $1M comfortably; standard middle-class households typically need $1.5-2.5M.

What is FIRE (Financial Independence, Retire Early)?

FIRE = accumulating 25x your annual expenses (the inverse of 4% withdrawal rule) so you can stop earning. Variants: Lean FIRE (low spending, smaller target), Fat FIRE (luxury spending, $3M+), Coast FIRE (stop saving, let compounding finish), Barista FIRE (semi-retire with part-time income).

Do I need a financial advisor for retirement planning?

For simple situations (single country, salary employee, no equity comp): a low-cost robo-advisor at 0.25% AUM is usually enough. For complex situations (cross-border, business income, large equity comp, divorce, sudden inheritance): a fee-only fiduciary at $1,500-5,000/yr is often worth the cost.

What's the difference between active and passive retirement investing?

Active = picking funds/stocks trying to beat the market. Passive = buying low-cost index funds tracking the whole market. Over 15 years, 90%+ of professional active managers underperform their benchmark per SPIVA data. Most retirement portfolios should be 90%+ passive index funds.

How is retirement income taxed?

Traditional 401(k))/IRA/RRSP/SIPP withdrawals are taxed as ordinary income. Roth withdrawals are tax-free. Social Security (US)/State Pension (UK)/CPP (Canada) are partially or fully taxable depending on total retirement income. Plan to combine accounts strategically to stay in lower brackets.

Can I retire abroad to a lower-cost country?

Many retirees do - popular destinations include Portugal, Mexico, Costa Rica, Thailand, Malaysia. The cost-of-living savings can be 50-70% vs the US/UK. Tax residency, healthcare access, currency risk, and visa rules need careful analysis before relocating.

How do I plan for healthcare costs in retirement?

US retirees pre-65 typically need $300-500k of medical reserves to bridge to Medicare. Even single-payer countries (UK, Canada, Australia) involve out-of-pocket costs for dental, vision, long-term care, supplemental insurance. Budget 15-20% of retirement spend for healthcare.

What happens to my retirement savings when I die?

Most retirement accounts let you name a beneficiary who inherits the balance. Spouses get the most favorable treatment (roll into their own account). Non-spouse heirs in the US must drain inherited IRAs within 10 years (per SECURE Act). Update your beneficiary designations after any major life event.

Is the State Pension / Social Security enough to retire on?

Almost never. US Social Security replaces about 40% of pre-retirement income for an average earner. UK State Pension is around £11,500/year (~25-30% of median wage). India's EPS pension is capped near Rs 7,500/month. Treat government pensions as the inflation-adjusted bond portion of your retirement income; everything else is private savings.

Should I pay off my mortgage before retiring?

Mathematically, a 4-7% mortgage rate is close to the long-run expected return of a 60/40 portfolio, so the optimisation answer depends on rate, tax bracket, and expected return. Behaviourally, entering retirement mortgage-free reduces required income and sequence-of-returns risk. Many retirees use bonuses, RSU vests, and tax refunds in the 5-10 years before retirement to accelerate principal payoff.

When should I start drawing Social Security / state pension?

Each year of delay past full-retirement-age increases your benefit by 8% (US Social Security) up to age 70. If you have other savings and reasonable longevity, delaying until 70 maximises lifetime benefits. Claim early (62 in US) only if you NEED the income or have a short life expectancy.

Sources and methodology

Numbers on this page are sourced from official government / regulator websites and refreshed automatically every Sunday by our build pipeline. Hover any number with a dotted underline to see its source and as-of date.

Primary tax authority

Specific values cited

Reference	Value	Source	As of
`us.401k.catchup50`	$31,000	IRS	2026-01-01
`us.401k.limit`	$23,500	IRS	2026-01-01
`us.401k.supercatchup60`	$34,750	IRS	2026-01-01
`us.401k.total`	$70,000	IRS	2026-01-01

Methodology: each calculator linked from this post documents its formula. Live market data (FX, treasury yields, mortgage rates) is pulled from public APIs (exchangerate.host, FRED, BoE, ECB, BoC, CoinGecko, stooq).