The Solo 401(k): Most Powerful Account Self-Employed People Miss

Self-Employed · Solo 401(k)

3 MIN READ

The Solo 401(k):
the most powerful account most self-employed people miss.

If you're self-employed, a Solo 401(k) lets you contribute up to $72,000 per year tax-advantaged, dramatically more than a traditional 401(k) or IRA. Here's how it works and who qualifies.

READING TIME: 6 MIN

THE SHORT VERSION

A Solo 401(k) is a 401(k) for one-person businesses. You contribute as both employee ($24,500 limit) and employer (up to 25% of compensation). Combined limit: $72,000 in 2026. The highest contribution limit available to individuals. If you're self-employed and not using this, you're overpaying taxes.

This page covers US-specific accounts and tax law.

Who qualifies

Any self-employed person with no full-time employees (other than a spouse) 🔍 verify×DON'T TRUST, VERIFYClaim: Solo 401(k) requires self-employment with no full-time employees other than spouse.Verify at: IRS One-Participant 401(k) ↗Once you hire a full-time employee (excluding spouse), the plan must convert to a standard 401(k)..

Includes: freelancers, consultants, independent contractors, sole proprietors, single-member LLCs, S-corp owners, side-gig income.

You do not need to be full-time self-employed. If you have a W-2 job AND self-employment income, you can have both a workplace 401(k) AND a Solo 401(k).

The two contribution buckets

EMPLOYEE CONTRIBUTION

Up to $24,500 in 2026 (same limit as regular 401(k)). Can be Traditional (pre-tax) or Roth (after-tax). This limit is shared across all your 401(k) plans combined. If you have a W-2 401(k), those contributions count against this limit 🔍 verify×DON'T TRUST, VERIFYClaim: 2026 employee 401(k) deferral limit is $24,500, shared across all plans.Verify at: IRS 401(k) limits ↗Indexed for inflation..

EMPLOYER CONTRIBUTION

Up to 25% of your self-employment compensation (net SE income after half the SE-tax deduction for a sole proprietor). Always pre-tax. See IRS Publication 560 ↗ for the exact calculation.

COMBINED 2026 LIMIT

$72,000 (under 50) / $80,000 (50+ with catch-up).

The Mega Backdoor Roth

Some Solo 401(k) plans allow after-tax contributions beyond the Roth employee limit, which can then be converted to Roth inside the plan. Not all plans support this.

Fidelity's Solo 401(k) supports the Mega Backdoor Roth 🔍 verify×DON'T TRUST, VERIFYClaim: Fidelity's Solo 401(k) plan document supports Mega Backdoor Roth conversions.Verify at: Fidelity Solo 401(k) ↗Check current plan document. Features change.. This is one of the most powerful tax strategies available to high-income self-employed people.

Bitcoin in a Solo 401(k)

A self-directed Solo 401(k) can hold Bitcoin directly (not via ETF). More complex to set up. Requires a specialized custodian. Typically only worth the complexity at large balances ($100k+).

Simpler option: regular Solo 401(k) at Fidelity, hold IBIT or FBTC inside it for Bitcoin exposure without self-custody complexity. See Bitcoin ETF Guide.

Where to open one

Fidelity: free, no ongoing fees, good fund selection, supports Mega Backdoor Roth.
Vanguard: good but less flexible.
Charles Schwab: good option.
Avoid: providers charging high setup or annual fees.

The deadline

Solo 401(k) must be established by December 31 of the tax year you want to make contributions for. Contributions can be made until the tax filing deadline (including extensions) 🔍 verify×DON'T TRUST, VERIFYClaim: Solo 401(k) plan must be established by Dec 31; contributions can be made until tax filing deadline.Verify at: IRS Solo 401(k) ↗SECURE Act 2.0 changed some rules; verify current deadlines..

→ Accounts: Solo 401(k) Deep Dive → Tax Strategy → Side Income → Paycheck Optimizer

Last updated 2026-04-22. Not financial or tax advice. Consult a CPA before setting up.

The Solo 401(k):the most powerful account most self-employed people miss.