What Is a Mega Backdoor Roth?
A Mega Backdoor Roth may let an eligible employee move additional after-tax 401(k) contributions into Roth treatment, but the workplace plan must support the necessary after-tax contribution and conversion or rollover features.
Why it is different
Regular 401(k) elective deferrals are limited separately from the overall defined-contribution plan limit. If a plan supports after-tax contributions, the space between the employee deferral, employer contributions, and the overall limit may be available for an after-tax strategy.
Plan features are decisive
The plan must allow after-tax contributions and either in-plan Roth conversions or distributions that can be rolled to a Roth account. Many plans do not offer all of these features.
2026 limits
The 2026 defined-contribution plan limit is $72,000. The amount potentially available depends on elective deferrals, employer contributions, and plan rules.
Frequently asked questions
Can everyone use a Mega Backdoor Roth?
No. It depends on the specific employer plan features and your contribution room.
Is a Mega Backdoor Roth the same as a Backdoor Roth?
No. A Backdoor Roth generally uses an IRA contribution and conversion; a Mega Backdoor Roth uses after-tax workplace-plan contributions.
Sources
Gleefund explains general retirement-account concepts and provides estimates. It does not provide financial, tax, or legal advice. See our disclaimer and methodology. Check the current IRS rules before acting.
Figures current as of 2026-09-25. Found an error? Contact us.