2. Solo 401(k)

Best for: A business owner or self-employed person with no employees (except a spouse, if applicable).

Contribution limit: For 2020, it’s up to $57,000, plus a $6,500 catch-up contribution for those 50 or older, or 100% of earned income, whichever is less. For 2021, it’s $58,000 in 2021, plus a $6,500 catch-up contribution or 100% of earned income, whichever is less. To help understand the contribution limits here, it helps to pretend you’re two people: An employer (of yourself) and an employee (also of yourself).

• In your capacity as the employee, you can contribute as you would to a standard employer-offered 401(k), with salary deferrals of up to 100% of your compensation or $19,500 (plus that $6,000 catch-up contribution, if eligible), whichever is less.

• In your capacity as the employer, you can make an additional contribution of up to 25% of compensation.

• There is a special rule for sole proprietors and single-member LLCs: You can contribute 25% of net self-employment income, which is your net profit less half your self-employment tax and the plan contributions you made for yourself.

• The limit on compensation that can be used to factor your contribution is $285,000 in 2020 and $290,000 in 2021.

Tax advantage: This plan works just like a standard, employer-offered 401(k): You make contributions pretax, and distributions after age 59½ are taxed

Employee element: You can’t contribute to a solo 401(k) if you have employees. But you can hire your spouse so they can also contribute to the plan. Your spouse can contribute up to the standard employee 401(k) contribution limit, plus you can add in the employer contributions, for up to an additional $57,000 total in 2020 or $58,000 total in 2021, plus catch-up contribution, if eligible. This potentially doubles what you can save as a couple.

How to get started: You can open a solo 401(k) at many online brokers. You’ll need to file paperwork with the IRS each year once you have more than $250,000 in your account.

The details

This plan, which the IRS calls a “one-participant 401(k),” is particularly attractive for those who can and want to save a great deal of money for retirement or those who want to save a lot in some years — say, when business is flush — and less in others.

Keep in mind that the contribution limits apply per person, not per plan — so if you also have outside employment that offers a 401(k), or your spouse does, the contribution limits cover both plans.

One other thing to know: You can also choose a solo Roth 401(k), which mimics the tax treatment of a Roth IRA. Again, you might go with this option if your income and tax rate are lower now than you expect them to be in retirement.

3. SEP IRA

Best for: Self-employed people or small-business owners with no or few employees.

Contribution limit: The lesser of $58,000 in 2021 ($57,000 in 2020) or up to 25% of compensation or net self-employment earnings, with a $290,000 ($285,000 in 2020) limit on compensation that can be used to factor the contribution. Again, net self-employment income is net profit less half of your self-employment taxes paid and your SEP contribution. No catch-up contribution.

Tax advantage: You can deduct the lesser of your contributions or 25% of net self-employment earnings or compensation — limited to that $290,000 cap per employee in 2021 — on your tax return. Distributions in retirement are taxed as income. There is no Roth version of a SEP IRA.

Employee element: Employers must contribute an equal percentage of salary for each eligible employee, and you are counted as an employee. That means if you contribute 10% of your compensation for yourself, you must contribute 10% of each eligible employee’s compensation.

Get started: You can open a SEP IRA at many online brokers just as you would a traditional or Roth IRA, with a few extra pieces of paperwork.

The details

A SEP IRA is easier than a solo 401(k) to maintain — there’s a low administrative burden with limited paperwork and no annual reporting to the IRS — and has similarly high contribution limits. Like the solo 401(k), SEP IRAs are flexible in that you do not have to contribute every year.

The downside for you, as the business owner, is that you have to make contributions for employees, and they must be equal — not in dollar amount, but as a percentage of pay — to the ones you make for yourself. That can be costly if you have more than a few employees or if you’d like to put away a great deal for your own retirement. You cannot simply use a SEP to save for yourself; if you contribute for the year, you have to make contributions for all eligible employees.

4. SIMPLE IRA

Best for: Larger businesses, with up to 100 employees.

Contribution limit: Up to $13,500 in 2021 and 2020 (plus catch-up contribution of $3,000 if 50 or older). If you also contribute to an employer plan, the total of all contributions can’t exceed $19,500.

Tax advantage: Contributions are deductible, but distributions in retirement are taxed. Contributions made to employee accounts are deductible as a business expense.

Employee element: Unlike the SEP IRA, the contribution burden isn’t solely on you: Employees can contribute through salary deferral. But employers are generally required to make either matching contributions to employee accounts of up to 3% of employee compensation, or fixed contributions of 2% to every eligible employee. Choosing the latter means the employee does not have to contribute to earn your contribution. The compensation limit for factoring contributions is $290,000 in 2021 ($285,000 in 2020).

Get started: The process is similar to a SEP IRA — you can open a SIMPLE at an online broker, with a heavier paperwork load than your standard IRA.

The details

If you’re the owner of a midsize company with fewer than 100 employees, the SIMPLE is a fairly good option, as it’s easy to set up and the accounts are owned by the employees.

SIMPLE IRA contribution limits are significantly lower than a SEP IRA or solo 401(k), however, and you may end up having to make mandatory contributions to employee accounts, which can be expensive if you have a large number of employees who participate. Here’s more on the SIMPLE IRA vs. a 401(k).

The SIMPLE IRA is also inflexible, particularly early on: Early withdrawals, before age 59½, are treated the same as early 401(k) or IRA distributions, in that they are taxed as income and subject to 10% penalty. But if you make a withdrawal within the first two years of participation in a SIMPLE IRA, the 10% penalty is increased to 25%. That means you also can’t roll over a SIMPLE to another retirement account within that two-year period. Zing.

One other thing to know: There is a 401(k) version of a SIMPLE, which works in much the same way but allows participants to take loans from their accounts. This version requires more administrative oversight and can be more expensive to set up.

5. Defined benefit plan

Best for: A self-employed person with no employees who has a high income and wants to save a lot for retirement on an ongoing basis.

Contribution limit: Calculated based on the benefit you’ll receive at retirement, your age and expected investment returns.

Tax advantage: Contributions are generally tax deductible, and distributions in retirement are taxed as income. An actuary must figure your deduction limit, which adds an administrative layer.

Employee benefit: If you have employees, you generally offer this plan to them and make contributions on their behalf.

Get started: Your options for brokerages are more limited than with the above accounts, but Charles Schwab offers defined benefit plans.

The details

We often lament the decline of pension plans, and this is exactly that: If you’re self-employed, you can set up your own pension — a guaranteed stream of income — in retirement by using a defined benefit plan.

So why wouldn’t everyone do it? They’re expensive, with high setup and annual fees. If you have employees, that fee will likely go up, and you’ll need to contribute on their behalf. They carry a heavy administrative burden each year, and they require a commitment to fund the plan with a certain amount per year. If you need to change that amount, you’ll pay additional fees.

The upside is that you can stash a lot of cash in these, so if you’re fairly close to retirement, earning a high income that you know you’ll maintain and that allows you to save a significant amount per year — we’re talking $50,000 to $80,000 or more — you might consider using this plan to supercharge your savings efforts.

Where to open a retirement plan if you’re self-employed

Once you’ve decided to open one of these accounts, you’ll have to decide where to do it.

Most online brokers will allow you to open the four most common account types: IRA, solo 401(k), SEP IRA and SIMPLE IRA. The account providers in our analysis of the best IRA providers are all good choices.

Each broker will walk you through the process of opening one of these accounts and explain any paperwork you may need to file with the IRS. But to be on the safe side, you may also want to work with an accountant.