Roughly one in four employer 401(k) plans include the features needed to run a mega backdoor Roth, so the companies that offer the mega backdoor Roth tend to be large employers with sophisticated benefits teams. Major technology firms including Google, Microsoft, Amazon, Apple, Meta, Salesforce, Oracle, Intel, Cisco, IBM, Intuit, PayPal, Stripe, Block, LinkedIn, Uber, and Nvidia are widely reported to support it. Outside tech, Goldman Sachs, Wells Fargo, Mastercard, McKinsey, Boeing, AT&T, Target, Johnson & Johnson, Netflix, and Exelon are commonly cited as well.
Plan features change year to year, so treat any list as a starting point and confirm with your own benefits team before counting on the strategy.
What a Plan Needs to Qualify
Two provisions have to appear together. First, the plan must allow voluntary after-tax contributions, which sit in a separate bucket from pre-tax and Roth deferrals. Second, the plan must offer either an in-plan Roth conversion or an in-service distribution while you are still employed.1Internal Revenue Service. Rollovers of After-Tax Contributions in Retirement Plans Without both pieces, the after-tax money you contribute never converts to Roth, and its future earnings get taxed as ordinary income at withdrawal instead of growing tax-free.
The size of the opportunity comes from Internal Revenue Code Section 415(c), which caps total additions to your 401(k) at $72,000 in 2026.2Internal Revenue Service. IRS Notice 2025-67 – 2026 Amounts Relating to Retirement Plans and IRAs Your elective deferrals (up to $24,500) plus any employer match rarely fill that ceiling, and voluntary after-tax contributions can occupy the remainder. Converting them promptly moves the whole amount into a Roth account.
Technology Companies
Tech is where the strategy is most reliably available. Amazon’s plan through Fidelity is known for an automatic conversion feature that moves after-tax dollars into Roth on the same day they arrive, which keeps taxable earnings near zero. Google’s plan allows both in-plan Roth conversions and in-service distributions. Microsoft’s plan carries the full toolkit: pre-tax or Roth deferrals, employer match, and after-tax contributions that can be converted.
Apple, Meta, Salesforce, Oracle, Intel, Cisco, IBM, Intuit, PayPal, Stripe, Block (Square), LinkedIn, Uber, and Nvidia are also commonly cited as offering the required combination. Exact mechanics vary — some run automatic conversions, others require you to trigger conversions manually — so check your Summary Plan Description for specifics.
Finance, Consulting, and Other Large Employers
Goldman Sachs explicitly allows after-tax contributions and provides an in-plan Roth 401(k) conversion option.3Goldman Sachs. Goldman Sachs 401(k) Plan Key Features The plan caps after-tax contributions at 25% of salary or bonus, up to a $15,000 per-plan limit, which is more restrictive than most tech plans. Wells Fargo, Mastercard, McKinsey, and several large consulting firms are also frequently named.
Outside financial services, Boeing, AT&T, Target, Johnson & Johnson, Netflix, and Exelon reportedly offer some version of the feature. The common thread is scale: administering after-tax contributions and Roth conversions adds compliance cost, so it skews to employers with thousands of participants and dedicated benefits staff.
Why So Few Plans Offer It
Among plans recordkept by Vanguard, only 24% allowed voluntary after-tax contributions in 2024, and just 10% offered automatic in-plan Roth conversions — the feature that makes the strategy painless.4Vanguard. How America Saves 2025 Even among plans that permit after-tax contributions, only a subset also provide a conversion pathway.
The reasons are administrative and regulatory. After-tax contributions trigger additional non-discrimination testing that many sponsors would rather avoid. Smaller employers are especially reluctant because the cost of failed testing falls on the company. If you are weighing job offers partly on retirement benefits, this is a meaningful differentiator worth asking about during the hiring process.
How to Confirm Your Own Plan Qualifies
Start with the Summary Plan Description, the legal document your employer must provide describing what the plan covers and how it works.5U.S. Department of Labor. Plan Information Most employers post it on their benefits portal. Search the document for “after-tax contributions” and for either “in-service withdrawal” or “in-plan Roth conversion.” Both terms present means the plan likely supports the strategy. Either missing means it does not.
Then log into your 401(k) account on your custodian’s site (Fidelity, Vanguard, Schwab, or another) and open the contribution election page. You should see a separate option for after-tax contributions beyond the standard pre-tax and Roth choices. If only pre-tax and Roth appear, after-tax contributions probably are not enabled. Some plans hide the option under an “advanced” or “additional contributions” menu.
Call your benefits administrator if anything is unclear. They can confirm what the plan allows and calculate your personal after-tax room after accounting for your deferrals and employer match.
Caps That Shrink the Theoretical Maximum
Even at companies that offer the feature, highly compensated employees often cannot contribute the full amount the math suggests. The IRS requires plans to pass the Actual Contribution Percentage test, which compares contributions by highly compensated employees to those made by everyone else.6Internal Revenue Service. 401(k) Plan Fix-It Guide – The Plan Failed the 401(k) ADP and ACP Nondiscrimination Tests For 2026, you count as highly compensated if you earned more than $160,000 in the prior year.2Internal Revenue Service. IRS Notice 2025-67 – 2026 Amounts Relating to Retirement Plans and IRAs
When rank-and-file participation is low, the ACP test can force the plan to refund excess after-tax contributions to highly compensated employees after year-end. To avoid that, many companies preemptively cap after-tax contributions at a percentage of salary or a fixed dollar amount. Goldman Sachs is one example, with its $15,000 ceiling.3Goldman Sachs. Goldman Sachs 401(k) Plan Key Features Others use percentage-of-pay limits. Your actual after-tax room may be well below the theoretical Section 415(c) headroom.
A Note on Legislative Risk
The mega backdoor Roth has come close to being eliminated. Proposals in Congress in 2021 would have banned Roth conversions of after-tax money in retirement accounts, and while those provisions did not pass, the strategy remains a recurring target in tax reform discussions. It benefits almost exclusively higher earners, which keeps it politically visible. If your plan offers the feature, the conventional view is to use it while it is available rather than assume it will stay in place indefinitely.