Can I Open a 401(k) on My Own Without an Employer?

Yes. If you earn self-employment income and have no employees other than a spouse, you can open a 401(k) without an employer by setting up a Solo 401(k), sometimes called an Individual 401(k). You act as both the employee and the employer, which gives you two separate ways to contribute and a combined ceiling of $72,000 in 2026, higher with catch-ups.

Who Can Open One

The Solo 401(k) is built for one-person businesses. Sole proprietors, single-member LLCs, partnerships with no outside employees, and S-corps where only the owner draws a salary all qualify. The income can come from freelancing, consulting, running a small business, or any trade where your personal services generate the revenue.¹

The IRS calls this a “one-participant retirement plan”: one that covers only a single individual, or that individual and their spouse, where the owner holds 100 percent of the business.¹ A working spouse can participate in the same plan, which effectively doubles your household’s contribution capacity, since each of you gets a full employee deferral and profit-sharing allocation.

What you don’t need: a W-2 job, an LLC, or a full-time business. A side gig that produces net self-employment earnings is enough. What disqualifies you is having a common-law employee, other than a spouse, who meets the plan’s eligibility rules.

How Much You Can Contribute in 2026

Because you fill both roles, contributions come in two layers.

As the Employee

You can defer up to $24,500 of your earned income for 2026. If you are 50 or older, add a catch-up of $8,000 for a personal deferral of $32,500. Participants aged 60 through 63 get a larger SECURE 2.0 catch-up of $11,250, taking their deferral to $35,750.²

As the Employer

Wearing your employer hat, you can add a profit-sharing contribution capped at 25 percent of compensation as defined by the plan.³ For self-employed individuals, “compensation” means your net self-employment earnings minus the deductible half of your self-employment tax. Because the contribution itself also reduces earned income, the effective cap for a sole proprietor lands at roughly 20 percent of net self-employment income before that adjustment.

The Combined Ceiling

Employee deferrals plus employer contributions cannot exceed $72,000 in 2026. Catch-ups sit on top of that number, so the total maximum is $80,000 if you are 50 or older and $83,250 for those 60 through 63. The plan can consider up to $360,000 of compensation when calculating contributions.⁴ These figures adjust for inflation each year.

Traditional or Roth

Most Solo 401(k) plans let you choose traditional (pre-tax) deferrals, Roth (after-tax) deferrals, or a split. Traditional contributions reduce your taxable income now and are taxed when withdrawn. Roth contributions are taxed now and grow tax-free, with qualified withdrawals (generally after age 59½ and five years from your first Roth contribution to the plan) coming out tax-free.

Since 2023, the SECURE 2.0 Act also allows plans to designate employer profit-sharing contributions as Roth. If you elect this, the profit-sharing amount is taxable income in the year contributed, then grows and comes out tax-free.⁵ Your plan document has to specifically permit Roth employer contributions.

How to Set the Plan Up

The paperwork is lighter than it sounds because most brokerage firms offer pre-approved plans that carry IRS-reviewed language.⁶

Get an EIN

You need an Employer Identification Number to identify the plan. Sole proprietors without employees sometimes use a Social Security number for the business itself, but an EIN is generally required for a retirement plan trust. You can apply online at no cost and receive it within minutes.⁷

Pick a Provider and Sign the Adoption Agreement

Choose a brokerage or plan administrator and complete two documents. The adoption agreement is the plan’s core contract, recording your choices on eligibility, contribution types (traditional, Roth, or both), how employer contributions are allocated, vesting, and distributions. The basic plan document is the broader legal framework governing the trust; the provider supplies it and you keep a copy.⁶

Name a Trustee and Open the Account

You must name a trustee to oversee plan assets, which in a Solo 401(k) is almost always you. After signing the adoption agreement, submit it to your financial institution to open the brokerage or custodial account that will hold the investments. Keep signed and dated copies of every plan document, plus any later amendments, permanently.⁶

Deadlines That Decide Whether This Year Counts

Miss the wrong date and you lose an entire year of contributions.

Plan establishment: Corporations and partnerships generally must adopt the plan by December 31 of the tax year you want the first contributions to count for. Sole proprietors may have until their tax filing deadline (not including extensions) to both establish and fund the plan for employee deferrals.
Employee deferrals: These typically must be made by December 31, since they represent compensation you chose to redirect during the year.
Employer profit-sharing: You can fund these up to your business’s tax filing deadline, including extensions. For a sole proprietor filing a personal return with an extension, that means as late as October 15.

If you are setting up late in the year, confirm the specific dates with your provider, because they shift slightly by business structure.

Bringing Old Retirement Money In

You can usually roll a traditional IRA or a former employer’s 401(k) into your Solo 401(k), but only if your plan document allows incoming rollovers. Check before initiating the transfer.⁸ Direct rollovers from a workplace plan and trustee-to-trustee transfers from an IRA avoid tax withholding; a 60-day rollover involves receiving the funds yourself and depositing them within 60 days, with 20 percent typically withheld if the source is a workplace plan. Required minimum distributions and hardship withdrawals cannot be rolled over.

Rolling a traditional IRA into a Solo 401(k) also removes pre-tax IRA balances from the pro-rata calculation, which matters if you later plan a “backdoor” Roth IRA conversion.

What Ends the Solo Status

The Solo 401(k) works only while you have no eligible employees. Under standard retirement plan rules, an employee who completes a year of service with at least 1,000 hours generally becomes eligible.¹ Once that happens, you must include them, and the plan stops being a one-participant plan.⁹

Independent contractors and part-time workers who stay under 1,000 hours a year don’t trigger this. Once anyone crosses the threshold, the plan becomes subject to nondiscrimination testing and the compliance rules that apply to multi-participant plans, unless you convert to a safe harbor design.⁹ If you own more than one business, employees across all of them count, because the tax code treats companies under common ownership as a single employer for retirement plan purposes.¹⁰

Annual Filing: Form 5500-EZ

One of the practical advantages of running your own plan is lighter reporting. You are exempt from the ERISA filings that larger plans face and instead use the simplified Form 5500-EZ when required.¹¹

File Form 5500-EZ for any plan year in which total plan assets exceed $250,000 at year-end. If you maintain more than one one-participant plan, combine the assets to test the threshold.¹² You also file for the plan’s final year regardless of asset level.

Late filing carries a penalty of $250 per day, up to $150,000 per return.¹³ If you have missed a filing, the IRS runs a voluntary penalty relief program that is far cheaper than waiting to be contacted.

1
Office of the Law Revision Counsel. 26 USC 401 – Qualified Pension, Profit-Sharing, and Stock Bonus Plans
2
Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
3
Office of the Law Revision Counsel. 26 USC 404 – Deduction for Contributions of an Employer to an Employees Trust or Annuity Plan and Compensation Under a Deferred-Payment Plan
4
Internal Revenue Service. Notice 25-67 – 2026 Amounts Relating to Retirement Plans and IRAs
5
Internal Revenue Service. SECURE 2.0 Act Impacts How Businesses Complete Forms W-2
6
Internal Revenue Service. Pre-Approved Retirement Plans – Adopting Employer
7
Internal Revenue Service. Get an Employer Identification Number
8
Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions
9
Internal Revenue Service. One-Participant 401(k) Plans
10
Office of the Law Revision Counsel. 26 USC 414 – Definitions and Special Rules
11
Internal Revenue Service. About Form 5500-EZ, Annual Return of a One-Participant Retirement Plan or a Foreign Plan
12
Internal Revenue Service. Instructions for Form 5500-EZ
13
Internal Revenue Service. Penalty Relief Program for Form 5500-EZ Late Filers