Open a solo 401k plan online in under 10 minutes – The Carry Solo 401k Plan is a featured-packed self-directed account that lets you invest in both traditional and alternative assets, take out a loan, or do a mega backdoor Roth conversion with a few clicks.

A solo 401k plan is only as good as what features your provider can offer you. Every solo 401k plan provider is different in the number of benefits and level of support offered. 

Low-cost or free plans, also called prototype plans, often don’t offer desirable features like the ability to make Roth contributions, take solo 401k loans, or have checkbook control over your investments. Most solo 401k plans offered by major banks and brokerages are basic prototype plans that limit your investment options and have minimum features.

Premium self-directed plans, also called non-prototype plans, offer a much wider range of benefits such as a Roth account, unlimited investment options, and higher levels of support. Fees can often be higher than prototype plans, but typically give users more tax savings, and higher return potentials through investments in alternative assets.

If you’re looking to open a solo 401k, here’s a look at the best solo 401k plan providers comparing price, features offered, customer support, and user experience.

What to look for in a solo 401k provider

If you’re opening a solo 401k, it’s important to make sure that the provider can offer you the biggest tax benefits that normally comes with a solo 401k plan.

Ideally, your solo 401k plan provider should provide the following benefits:

  1. A Roth option
  2. The ability to do a mega backdoor Roth solo 401k
  3. Unrestricted investment options
  4. The ability to do rollovers
  5. Account set up and administration support
  6. Self-directed with checkbook control

1. A Roth option

A solo 401k gives you the ability to make large Roth contributions. A Roth account lets you contribute in post-tax dollars, and enjoy tax-free withdrawals in retirement. If you’re investing in assets with higher-return potentials (like crypto, private equity, or real estate), not having to pay any taxes on the gains after compounding tax-free in your account for years can save you significantly more in taxes than traditional contributions.

In 2024, you can contribute up to $23,000 into a Roth solo 401k. If you’re 50 years of age or older, you can contribute up to $30,500.

In comparison, a Roth IRA only has a contribution limit of $7,000 ($8,000 if age 50+) for 2024.

Not all solo 401k plans let you contribute to a Roth solo 401k. If Roth contributions are important to you, make sure that the plan you choose comes with a Roth option.

2. The ability to do a mega backdoor Roth solo 401k

Because a Roth account is so tax advantaged, some people prefer putting as much money into a Roth account as possible.

As mentioned above, the contribution limit of a Roth solo 401k is $23,000 for 2024. If you’re at least 50, you get an additional $7,500 in catch-up contributions, bringing your total limit to $30,500.

The solo 401k contribution limit is $69,000 for 2024, or $76,500 if you’re at least 50 years of age. Of that amount, only $23,000 ($30,500 if age 50+) is allowed to be made in Roth dollars.

mega backdoor Roth solo 401k allows you to contribute the full amount of the solo 401k contribution limit into a Roth account. Essentially, you can put in up to $69,000 ($76,500 if age 50+) into a Roth solo 401k for 2024 if you choose to do the mega backdoor.

In order to be able to do the mega backdoor Roth solo 401k, your plan provider has to be specifically set up to offer the option, and must be provide two features in order to do so:

  1. Offer the ability to make contributions to an after-tax account.
  2. Offer the option to do in-service distributions.

A mega backdoor Roth solo 401k involves many steps and can get complex to execute on your own. The best solo 401k plan providers provide higher levels of support and will help you implement the mega backdoor and file the necessary tax forms.

3. Unrestricted investment options

The IRS lets you invest in whatever asset class you want with a solo 401k. You have total investment freedom, and the only things you’re not allowed to invest in are collectibles and life insurance. You can invest in things like stocks, crypto, real estate, or even write checks to invest in startups.

Most prototype low-fee plans offered by major banks do not give you full investment control, and you’re limited by whatever options they provide in their plans. In order to invest in alternative assets, you should look for a plan provider that gives you full investment control over your account with no restrictions.

Also read: What Can I Invest In with a Solo 401k?

4. The ability to do rollovers

rollover is one of the fastest, easiest ways to fund a solo 401k, and can accept rollovers from any retirement plan except a Roth IRA (per IRS rules). If you have funds in an old 401k, SEP IRA, or even a traditional IRA, you can rollover your funds and assets into a solo 401k, and immediately open the door to more investment options.

There’s no limit on how much you can rollover, and it does not affect your contribution limits for the year. For example, you could rollover $100,000 from another retirement plan and still have the full contribution room left over to add even more money to your account.

5. Account set up and administration support

A solo 401k is generally more complex to set up than other retirement plans like an IRA or SEP IRA. There’s more paperwork involved in and requires more steps (like opening separate bank and brokerage accounts), especially if it’s a self-directed account. One of the reasons why a solo 401k is not as popular is because of the complexity in setting one up.

Sure, a prototype plan at a major bank is easy to set up, but opening a non-prototype plan involves a complex set up process, including opening separate bank and brokerage accounts for your solo 401k trust.

Your plan provider should ideally offer account set up support and administration help for maintaining your plan and staying in compliance.

6. Self-directed account with checkbook control

One of the most powerful features of a solo 401k is that it can come as a self-directed account and even offer checkbook control. Not many people are familiar with checkbook control retirement accounts, so here’s a quick summary on what it means.

When you open a self-directed solo 401k plan with checkbook control, you get separate bank and brokerage accounts for your solo 401k trust. All investments made in your account belong to your solo 401k trust, and not you, the individual. As the trustee of the account, you get full control over the checkbook and can write checks and wire funds directly when you want to make an investment.

For example, if you want to invest in cryptocurrencies through your solo 401k, you would open a new account with a crypto exchange under your solo 401k trust, and then send the funds into your account from your solo 401k bank account. If you want to invest in a startup or an investment property, you could write a check directly from your solo 401k bank account.

Typically, with most checkbook control solo 401k plan providers, they’ll create the plan documents for you, but you’ll have to go out and look for a third party bank and brokerage that will accept them and open your accounts for you. With the Carry Solo 401k, you get integrated brokerage accounts, so your accounts are created automatically for you when you sign up.

7. Solo 401k loan option

Only a few providers offer the ability to take a loan from your solo 401k. If they do, you can borrow up to 50% of your account value up to a maximum of $50,000. You have 5 years to repay the loan at prime rate plus one percent interest. If you use the funds to purchase a primary residence, you can get up to 15 years to pay it back. A solo 401k doesn’t affect your credit score and the application process is quick since you’re borrowing from your own account, not a third party creditor.

Also read: How Much Does It Cost To Open a Solo 401k Plan? (Free vs Paid Plans)

The best solo 401k plan providers

Let’s compare solo 401k plan providers in 2024, for both free prototype plans and self-directed non-prototype plans.


The Carry Solo 401k Plan

  • Cost: $299/year. Zero asset under management fees when using the (optional) integrated brokerage account.
  • Roth option: Yes
  • Mega backdoor Roth solo 401k: Yes
  • Rollover options: Yes
  • Solo 401k loans: Yes
  • Traditional investment options: Any asset class, including alternative investments.
  • Alternative investments: Yes
  • Robo-advisor: Yes, Carry offers a no-fee robo-advisor

The Carry Solo 401k is a modern version of the solo 401k plan and removes any complexity in opening and contributing to an account. It has the most intuitive user interface, the easiest account set up process, best customer support, and an optional integrated investment platform.

Integrated investment platform

With a solo 401k, you typically have to go out and set up separate bank and brokerage accounts for your solo 401k trust. With Carry, you can use an integrated investment platform and brokerage accounts are set up automatically for you within your account.

You now also get the option to put your investing on autopilot using Carry’s no-fee robo-advisor.

Invest in any asset class, with checkbook control

Carry gives you full checkbook control over your solo 401k account so you can directly control your funds and invest in whatever asset you like.

Roth option

The Carry Solo 401k offers a full Roth option, allowing you to contribute up to $23,000 ($30,500 if age 50+) for 2024 into a Roth solo 401k plan.

Mega backdoor Roth option

Carry is one of the few plan providers that offer the ability to do the mega backdoor Roth solo 401k. In 2024, you could contribute up to $69,000 ($76,500 if age 50+) into a Roth account with Carry.

Rollover option

The Carry Solo 401k plan allows funding your account through a rollover from any retirement account, besides a Roth IRA (which is the only account that can’t rollover into a solo 401k, as per IRS rules).

Loan option

Carry is one of the few providers that allow you to take a solo 401k loan from your account. You can borrow up to 50% of your account value, up to a maximum dollar amount of $50,000. Because you’re borrowing from your own account, solo 401k loans don’t require any lengthy application processes or credit checks, and failure to repay the loan on time doesn’t affect your credit score. Interest rates on the loan are prime rate plus one or two percent, you can use the money for whatever you like, and you get 5 years to pay it back.

Recurring contributions and automatic investments

Carry is one of the only solo 401k plan providers that offer the ability to set automatic contributions and investments. You can literally set it and forget it, just like any W-2 employee that receives a 401k plan. Set the amount you want to contribute, the frequency you deposits to occur, and you can even automate investments.

Full account support and administration help

The best part about Carry is the account support and administration help. It has a modern user interface for an intuitive experience, and the set up process is easier than any other plan provider.

No AUM fees and no shady business

The Carry Solo 401k has simple pricing. There are no fees on assets under management when using the optional integrated brokerage account.

Everything done online

You can open an Carry account in under 10 minutes, completely online, with no paperwork required.

Financial advisory services

Because a solo 401k is so flexible, you may have confusion over how to prioritize your contributions (Roth or pre-tax). When you join Carry’s Professional Plan, you also get access to a financial planner who will assess your finances (and business if you have one), and then build you a personalized financial plan. Furthermore, you also get 24/7 access to your financial planner and can ask unlimited questions whenever you need help. Carry is the only company to provide this feature included as part of their plan.

Carry is the most advanced solo 401k plan that comes with a Roth option, optional integrated brokerage accounts, the best customer support, and the most intuitive user experience. Open an account in under 10 minutes. Learn more about the Carry Solo 401k.


Vanguard Solo 401k

  • Cost: $20 per fund, per year. Waived if your account value is over $50,000.
  • Roth option: Yes
  • Mega backdoor Roth solo 401k: No
  • Rollover options: Yes, but only IRAs.
  • Investment options: Only Vanguard mutual funds.
  • Alternative investments: No

Vanguard is a household name when it comes brokerages, and opening a solo 401k with them is quite simple. However, the Vanguard Solo 401k is an example of a prototype plan. Opening an account is much cheaper but your investment options are limited to just Vanguard mutual funds. You can’t invest in anything else, not even individual stocks and ETFs.

The Vanguard Solo 401k costs $20 per fund per year. This may sound cheap, but if you invest in several funds, the fees can start adding up. For example, if you invest in 10 different funds, that’s $200 per year. If you have $50,000 in assets, the fees are waived. Vanguard does offer a Roth option, but doesn’t have the ability to do a mega backdoor Roth.


Charles Schwab

  • Cost: Free
  • Roth option: No
  • Mega backdoor Roth solo 401k: No
  • Rollover options: Yes, but only a 401k.
  • Traditional investment options: Stocks, bonds, ETFs, mutual funds.
  • Alternative investments: No

Charles Schwab offers a free solo 401k. Unfortunately, it’s a prototype. While there are no costs for setting up an account, there there is no Roth option, no ability to do a mega backdoor Roth solo 401k, and limited investment choices. You can’t invest in alternative assets like real estate, crypto, or private equity. Rollovers are allowed, but you can only rollover a 401k and you can’t rollover an IRA or SEP IRA.


E-trade

  • Cost: Free
  • Roth option: Yes
  • Mega backdoor Roth solo 401k: No
  • Rollover options: Yes
  • Traditional investment options: Stocks, bonds, ETFs, mutual funds.
  • Alternative investments: No

E-trade is one of the only prototype solo 401k plans that actually offer great benefits. There’s a Roth option, ability to do rollovers, and no set up fees. While you have a wider selection of investment options, you’re limited to stocks, bonds, mutual funds, and ETFs. You cannot invest in alternative assets. Users have also reported that they’re having trouble making contributions within their accounts, so it’s best to check the current status of their user interface before signing up.


TD Ameritrade Solo 401k

  • Cost: Free
  • Roth option: No
  • Mega backdoor Roth solo 401k: No
  • Rollover options: Yes, but not from an IRA or SEP IRA
  • Traditional investment options: Stocks, bonds, ETFs, mutual funds.
  • Alternative investments: No

The TD Ameritrade Solo 401k is another low-cost solo 401k plan that lets users open a basic plan. There are no Roth contributions allowed, and you can only rollover funds from a 401k, 401a, 403a, 403b, 408, and 457b. You cannot rollover funds from an IRA or SEP IRA. Additionally, investment options are limited. You can choose from a selection of mutual funds and ETFs.


Fidelity Solo 401k

  • Cost: Free
  • Roth option: No
  • Mega backdoor Roth solo 401k: No
  • Rollover options: Yes
  • Traditional investment options: Stocks, bonds, ETFs, mutual funds.
  • Alternative investments: No

The Fidelity Solo 401k is a free prototype plan. There’s no Roth option or the ability to do a mega backdoor Roth solo 401k. Your investments are limited to stocks, ETFs, bonds, and mutual funds. One of the downsides of a Fidelity Solo 401k is that you must contribute to your account by mailing in a check. There is no ability to make contributions online directly through their admin panel.


My Solo 401k

  • Cost: $525 set up, $125 per year
  • Roth option: Yes
  • Mega backdoor Roth solo 401k: Yes
  • Rollover options: Yes
  • Traditional investment options: Stocks, bonds, ETFs, mutual funds.
  • Alternative investments: Yes

My Solo 401k has been around since 2009 and offers a non-prototype self-directed solo 401k plan. There’s a Roth option, the ability to do a mega backdoor Roth solo 401k, rollovers, and investment freedom to invest in alternative assets. When you sign up with My Solo 401k, they’ll create the solo 401k plan documents for you, but you’ll have to go out and find a third party bank that will accept them and open your accounts.


RocketDollar

  • Cost: $600 set up, $360 per year
  • Roth option: Yes
  • Mega backdoor Roth solo 401k: Yes
  • Rollover options: Yes
  • Traditional investment options: Stocks, bonds, ETFs, mutual funds.
  • Alternative investments: Yes

RocketDollar was started in 2018 and offers a solid solo 401k plan. It’s a little pricier than other non-prototype plans, but you have the option to open a lower tier-plan if you’re willing to sacrifice a few benefits. You get full investment freedom, the ability to do Roth contributions, and can invest in alternative assets like real estate and cryptocurrencies. While Rocket Dollar will create your plan documents for you, you’ll have to find a third party brokerage to accept the documents and open your accounts for you.


Ubiquity

  • Cost: $216 per year
  • Roth option: Yes
  • Mega backdoor Roth solo 401k: Yes
  • Rollover options: Yes
  • Traditional investment options: Stocks, bonds, ETFs, mutual funds.
  • Alternative investments: Yes

Ubiquity offers a self-directed solo 401k that gives you full checkbook control, letting you invest in traditional and alternative assets. You can make Roth contributions, do a mega backdoor Roth solo 401k, and rollover funds from existing retirement accounts. When you sign up with Ubiquity, they’ll create the solo 401k plan documents for you, but you’ll have to go find a third party bank or brokerage to accept them.


Comparing Roth solo 401k providers

All self-directed solo 401k plan providers offer a Roth option and the ability to invest in any asset class. That means you can invest in things like startups, real estate, and even cryptocurrencies through a Roth account and pay zero taxes when you withdraw in retirement.

The only two prototype plans that offer a Roth option are Vanguard and E-trade. However, Vanguard only lets you invest in Vanguard mutual funds, and e-trade only lets you invest in traditional assets like stocks, bonds, mutual funds, and ETFs.

Plan providers with Roth optionPriceInvestment optionsMega backdoor
Carry$299/yearAny asset classYes
Ubiquity$18/month ($216/year)Any asset classYes
Rocket DollarSilver Plan: $360 set up fee + $15/month
Gold Plan: $600 set up fee + $30/month
Any asset classYes
My Solo 401k$525 first fee + $125 annual feeAny asset classYes
Nabers$588/year – ($49/month)Any asset classYes
E-TradeFreeTraditional assetsNo
Vanguard$20 per fund per year (free if account value is over $50,000)Only Vanguard mutual fundsNo

Comparing free solo 401k plan providers

Most free plan providers are identical on paper. You can invest in traditional assets, but not alternative assets. Vanguard and E-trade come with a Roth option, but Vanguard only lets you invest your funds in Vanguard mutual funds, and nothing else.

Free plan providersPriceInvestment optionsRoth option
VanguardFree if account value is over $50,000Only Vanguard mutual fundsYes
Charles SchwabFreeTraditional assetsNo
FidelityFreeTraditional assetsNo
E-tradeFreeTraditional assetsYes
TD AmeritradeFreeTraditional assetsNo

Comparing self-directed solo 401k plan providers

All self-directed solo 401k plan providers offer premium features like a Roth option, mega backdoor Roth, and the ability to invest in any asset class, including alternative assets like crypto, real estate, and private equity.

With self-directed solo 401k plan providers, Carry is the only plan that offers an all-in-one experience through an integrated brokerage account. Other self-directed plan providers will create your solo 401k plan documents for you, and then you have to go and search for a third party bank or brokerage that will accept them and open your accounts.

Self-directed plan providersPriceIntegrated brokerageRoth option
Carry$299/yearYesYes
My Solo 401k$525 first fee + $125 annual feeNoYes
Nabers$588/year – ($49/month)NoYes
Rocket DollarSilver Plan: $360 set up fee + $15/month
Gold Plan: $600 set up fee + $30/month
NoYes
UbiquityStarts at $18/month ($216/year)NoYes

How to choose the right solo 401k plan provider for you

If you’re trying to decide which provider would be the best for you, here are some important questions to ask:

Do you want a Roth account?

The first thing to consider is if you want to make contributions to a Roth account, since many plan providers only offer a traditional (pre-tax) solo 401k account. The benefit of a Roth account is that your withdrawals in retirement are completely tax-free. You make contributions with post-tax dollars (income you’ve already paid taxes on), but any earnings in your account will be free from taxes when you withdraw in retirement.

Do you want the option to do a mega backdoor Roth conversion?

A mega backdoor Roth lets you contribute up to $69,000 ($76,500 if age 50+) into your Roth solo 401k for 2024, instead of just $23,000 ($30,500 if age 50+). For you to be able to do a mega backdoor Roth, the plan provider you choose has to specifically be set up to offer one through the use of an after-tax account.

What kind of investments are you looking to make?

Some plan providers let you invest in any asset class, while others only let you invest in traditional assets. If you’re only looking to make traditional investments into assets like stocks, bonds, mutual funds, and ETFs, the good news is that all plan providers (except Vanguard) offer this option. With Vanguard, you can only invest in Vanguard mutual funds.

If you also want to invest your solo 401k funds into alternative investments like cryptocurrencies, startups, private equity, real estate, and NFTs, then you would need to look into a self-directed solo 401k plan.

Are you okay with paying an annual fee in exchange for premium features and benefits?

As mentioned earlier, many prototype plans offered by major banks and institutions are free to set up. However, they don’t come with things like a Roth option, mega backdoor Roth, dedicated hands-on support, and the ability to invest in any asset class. If you’re not looking for any of these features, a prototype plan could be the more cost-effective option for you.

Do you want checkbook control?

Solo 401k plan providers that offer checkbook control allow you to take full control over your solo 401k bank and brokerage accounts’ checkbook. If you want to make an investment, there’s no need to request a custodian to send the funds; you can write a check or wire funds directly. Checkbook control is one of the most powerful features of a solo 401k, especially if you’re looking to be more versatile with your investments and put your funds into alternative assets.

Who qualifies for a solo 401k?

You can contribute to a solo 401k if you meet two requirements:

  1. You must have any form of self-employed activity.
  2. You must not have any employees who are at least 21 years of age, and have worked over 500 hours per year for 3 consecutive 12-month periods (excluding your spouse).

There are no income requirements, and you’re allowed to open a solo 401k even if you receive a 401k at work. For example, if you work at a company and receive a 401k plan, but you also have a weekend side hustle with no employees, you can open a solo 401k. A solo 401k has the highest contribution limits of any retirement plan, a Roth option, and full investment freedom to invest in any asset class you want.

Because you can contribute as both an employee and employer of your own business, you can typically max out contributions to a solo 401k with less income than similar retirement plans like a SEP IRA.

Are the contribution limits the same with all plan providers?

The solo 401k contribution limits are set annually by the IRS and they’re the same regardless of what plan provider you choose.

The solo 401k contribution limit for 2024 is $69,000 ($76,500 if age 50+).

The only difference in plans is if a provider offers a Roth account or not. If a Roth solo 401k is offered, you can contribute up to $23,000 ($30,500 if age 50+) for 2024. If a provider offers a mega backdoor Roth option, then you can contribute up to the full solo 401k contribution limit entirely into your Roth solo 401k.

If a plan provider does not offer a Roth option, you will only be able to make contributions to a pre-tax solo 401k account. Contributions to a pre-tax account are made with pre-tax income and is tax deductible from your taxable income for the year.

Note: Any plan provider that offers a Roth option also comes with a pre-tax option as well.

Is it possible to switch my solo 401k plan to a new provider?

Yes, if your current provider does not offer the benefits and features that you’re looking for, you can transfer your solo 401k account to another provider at any time. There are no penalties or taxes for transferring your plan from one provider to another.