Retirement Plans for the Self-Employed: SEP IRA vs Solo 401(k)
When you work for yourself, no one sets up your retirement or explains the options. Here is the self-employed playbook, SEP IRA vs solo 401(k), from someone still kicking himself for starting late.
Here is the thing nobody hands you when you start working for yourself: a retirement plan. There is no HR onboarding packet, no default account, no employer match quietly appearing. If you are a freelancer, contractor, or business owner, your retirement is entirely a decision you have to make on purpose, and the options have intimidating names that scare people off from ever starting.
I am living proof of the cost of that. I have two 401(k)s from past employers and a SEP IRA, but honestly, I did not understand the SEP IRA for a long time. It was not until I sat down properly with my accountant and my financial advisor that I really got how to use each account, how to maximize contributions, and how to squeeze the tax benefits out of them. I started later than I should have, in part because an early employer did not offer a 401(k) and nobody ever taught me what a SEP IRA even was. No one teaches you this stuff, which genuinely stinks, and I left real returns on the table because of it. Learn from that: the earlier you start, the better.
Your main options, decoded
You have more tools than you think. Here are the big ones for self-employed savers:
| Plan | Best for | The quick version |
|---|---|---|
| SEP IRA | Simplicity, higher earners | Contribute up to 25% of net earnings; almost no paperwork |
| Solo 401(k) | No-employee businesses | Employee + employer contributions; often saves more; Roth option |
| Roth / Traditional IRA | Getting started small | Lower limits, but dead simple and a fine first step |
A regular Roth or traditional IRA is a perfectly good place to begin if the others feel like a lot. But the two built for self-employment income, the SEP IRA and the solo 401(k), are where the real saving power is.
SEP IRA vs solo 401(k)
This is the decision most solo earners are actually weighing, so here is the honest comparison:
- SEP IRA is the easy button. You can open one in minutes, there is basically no annual paperwork, and you can contribute up to 25% of your net self-employment earnings. The catch is that it is all “employer” money, so at lower and moderate incomes you may not be able to put away as much.
- Solo 401(k) lets you contribute as both the “employee” and the “employer.” That employee piece means at moderate incomes you can often sock away more than a SEP allows. It also offers a Roth version and the ability to borrow from it. The trade-off is a bit more setup and, once the balance is large, an annual form.
The SEP IRA is simpler. The solo 401(k) usually lets you save more. That one sentence is most of the decision.
For a lot of one-person businesses, the solo 401(k) wins on pure saving power. But the best plan is the one you will actually open and fund, and a SEP IRA you use beats a solo 401(k) you keep meaning to set up.
Do not do this alone
Here is my honest regret, and it is not really about the accounts. It is that I was so focused on making money and growing my business that I never stopped to plan. I treated retirement as a someday-problem and should have done my own research, or hired an accountant and an advisor, years sooner. Not just for the tax strategy, but for the accountability, someone whose actual job is to make sure future-me gets set up.
I will be balanced about it: a financial advisor is not right for everyone, and plenty of people can handle this themselves. But there is a reason experts in their field exist, and a good one can genuinely change your outcome. The rules on contribution limits, deadlines, and how these accounts interact with any workplace plan get tricky, and the tax savings are big enough to more than pay for good advice. My accountant and advisor changed how I use these accounts. If you take one thing from my experience, let it be to get that help sooner than I did.
Where to go next
- Start with the big picture: how to save for retirement.
- Sitting on an old workplace plan? What to do with an old 401(k).
- Understand the core accounts: 401(k) vs IRA.
For the official rules and current contribution limits (they change most years), the IRS retirement plans center covers self-employed plans directly, and Investor.gov explains the basics without a sales pitch. This is general information, not personalized tax advice, so check your specifics with a pro.
Frequently asked questions
What is the best retirement plan for self-employed people?
It depends on your income and whether you have employees. For most solo earners, a SEP IRA is the simplest option with high contribution limits, while a solo 401(k) often lets you save more at moderate incomes and offers a Roth version. If you have no employees, a solo 401(k) is frequently the more powerful choice; if you want minimal paperwork, the SEP IRA wins.
SEP IRA vs solo 401(k): which is better?
A SEP IRA is simpler to open and maintain, with contributions of up to 25% of your net self-employment earnings. A solo 401(k) adds an employee contribution on top of that, so at moderate incomes you can often contribute more, and it offers a Roth option and loans. The solo 401(k) has slightly more paperwork. Many people choose the solo 401(k) for its higher saving potential.
Can I contribute to a SEP IRA and a 401(k)?
Yes, in many cases. If you have a workplace 401(k) from a job and also earn self-employment income, you can often contribute to both a SEP IRA (or solo 401k) for your self-employed work and your employer plan, subject to IRS limits. This is exactly the kind of question worth running past a tax professional.
How much can a self-employed person contribute to retirement?
Quite a lot. Both SEP IRAs and solo 401(k)s allow contributions well into the tens of thousands of dollars per year, far above a regular IRA, with the exact cap set by the IRS and adjusted most years. Your personal limit depends on your net earnings, which is why checking current IRS figures (or asking your accountant) matters.
