Several readers have asked me to explain the Mega Backdoor Roth strategy. I haven’t personally used it because most of my retirement savings went into my Traditional and Roth Thrift Savings Plan (TSP) accounts, and I later rolled my Roth TSP into a Roth IRA.
When I worked for the federal government, employees had access to a 401(a) plan that offered this opportunity. However, many private-sector employers that allow a Mega Backdoor Roth do so through a 401(k) plan.
But it’s an important strategy for many high-income earners, and for anyone whose employer’s retirement plan allows it, so let’s walk through how it works and a few things to know before deciding whether it’s right for you.
TL;DR
The Mega Backdoor Roth allows you to make after-tax contributions (and in some cases, a big lump sum payment) to certain employer-sponsored retirement plans and then move those dollars into a Roth IRA or Roth 401(k). Because the strategy uses your employer retirement plan’s much higher overall contribution limit, you may be able to save significantly more in Roth accounts than you could through a regular Roth IRA alone.
It’s legal, Boo!
The Mega Backdoor, Explained
The Mega Backdoor Roth is a tax-advantaged strategy that allows eligible employees to move after-tax contributions from certain employer-sponsored retirement plans into a Roth account.
In simple terms, you make after-tax contributions to an employer-sponsored retirement plan, such as a 401(k) or, in some cases, a 401(a), that allows after-tax contributions. You then convert those after-tax dollars to a Roth IRA or, if your plan permits, to a Roth account within the employer’s plan.
Unlike a traditional Roth IRA contribution, which is subject to annual contribution limits and income restrictions, the Mega Backdoor Roth takes advantage of your employer retirement plan’s much higher overall annual contribution limit.
Before we dive in, one quick disclaimer: Retirement plan rules vary by employer, so not everyone has access to this strategy.
Why People Use It
There are two common reasons people consider this strategy:
- Your income is too high to contribute directly to a Roth IRA.
- You want to save substantially more in Roth accounts than the normal annual Roth IRA contribution limit allows.
For reference, in 2026:
- The annual Roth IRA contribution limit is $7,500 (or $8,600 if you’re age 50 or older).
- Direct Roth IRA contributions begin to phase out based on your Modified Adjusted Gross Income (MAGI). For 2026, the phase-out range is $153,000–$168,000 for single/head of household filers and $242,000–$252,000 for married couples filing jointly.*
*When you’re within the phase-out range, you may still be eligible to make a partial Roth IRA contribution.
🐝 Budget Bee Tip
Don’t confuse a Backdoor Roth IRA with a Mega Backdoor Roth.
They sound similar, but they’re two different strategies. A traditional Backdoor Roth works through an IRA. A Mega Backdoor Roth uses after-tax contributions inside an employer-sponsored retirement plan that permits the strategy.
Here’s How It Works
Background
The Mega Backdoor Roth begins with after-tax contributions to an employer-sponsored retirement plan that allows them.
Because you’ve already paid income taxes on these contributions, you’re not taxed on the principal again.
However, any earnings that accumulate before the money is converted may be taxable when converted. That’s one reason many people complete the conversion shortly after making the after-tax contribution.
A Step-by-Step Overview
1. Make After-Tax Contributions
Once you’ve made your regular employee retirement contributions, and after accounting for any employer matching or other employer contributions, you may be able to make additional after-tax contributions if your retirement plan allows them.
The total amount that can go into your employer-sponsored retirement plan is subject to the IRS annual overall contribution limit (which is $72,000 in 2026, excluding eligible catch-up contributions).
2. Check Your Plan Rules
Not every retirement plan offers this strategy.
Verify that your employer’s plan allows:
- After-tax contributions
- In-service distributions and/or in-plan Roth conversions
Without these features, the Mega Backdoor Roth generally isn’t available.
3. Follow Your Plan’s Process
Every retirement plan has its own procedures.
Your Human Resources office, retirement plan administrator, or financial institution can explain exactly how to complete the process.
4. Convert to a Roth Account
Once the after-tax contributions have been made, you can generally move those dollars into:
- A Roth IRA, or
- A designated Roth account within your employer-sponsored retirement plan (if available).
This conversion is what gives the strategy its name: the “backdoor.”
Key Benefits
Higher Contribution Potential
The Mega Backdoor Roth may allow you to save substantially more in Roth accounts than a traditional Roth IRA alone.
Tax-Free Growth
Once inside the Roth account, qualified investments can grow tax-free.
Tax-Free Qualified Withdrawals
Qualified withdrawals from Roth accounts are generally tax-free in retirement.
Why Would You Do It?
You may want to consider a Mega Backdoor Roth if:
- You’ve already maxed out your TSP or 401(k) employee contributions
- You have additional money available to invest
- Your income prevents you from contributing directly to a Roth IRA
- You’d like more Roth savings for tax diversification in retirement
- You want investment choices beyond what your employer-sponsored retirement plan offers
If you’re still deciding whether to use a Mega Backdoor Roth, don’t let cash sit idle in a checking account earning little or no interest. A high-yield savings account (HYSA) can be a good temporary place to keep your money while you evaluate your options.
Before You Do It
Like many tax strategies, the Mega Backdoor Roth can be incredibly valuable, but only if your employer’s retirement plan allows it and it’s a good fit for your overall financial picture.
I’d recommend talking with a financial advisor or tax professional before moving forward. They can help determine whether this strategy makes sense for your circumstances and ensure you’re following your retirement plan’s procedures correctly.
🐝 That’s the buzz for today!