Does your employer's 401(k) plan allow AFTER-TAX contributions beyond the regular $24,500 employee limit?

Yes — I've confirmed it in my plan documents or with HR; Probably, but I haven't actually checked; No — my plan doesn't allow after-tax contributions

Does your plan let you move that after-tax money into a Roth account — via in-service withdrawals to a Roth IRA, or in-plan Roth conversions?

Yes — and ideally with frequent or automatic conversions; I think so, but I'm not sure how often it's allowed; No — neither option is available, or I haven't checked

Are you already maxing both your regular 401(k) AND your Roth IRA (direct or backdoor) every year?

Yes — both fully maxed; One of them maxed, the other partial; Neither is maxed yet

What's the foundation under all this — emergency fund and high-interest debt?

Solid 3–6 month emergency fund, no high-rate debt; Mostly there, but a few gaps; Still building — I have credit card debt or a thin emergency fund

How much extra cash do you have to put toward retirement each year, AFTER maxing your regular 401(k) and Roth IRA?

$25,000+ — I can fully use the after-tax space; $5,000–$25,000 — I could do a partial mega backdoor; Less than $5,000 extra

How does your current tax bracket compare to where you expect to land in retirement?

Lower now, higher later — locking in Roth at today's rate is a clear win; About the same; Higher now, lower later — Roth is less compelling for me

How many years until you plan to retire?

30+ years — I'm early in my career; 10 to 30 years — mid-career; Less than 10 years — I'm close to the finish line

How comfortable are you with the operational complexity — timing contributions, watching for excess, tracking conversion timing, filing 1099-Rs?

Comfortable — I'm willing to read plan docs and either DIY or pay a CPA; I'd figure it out, but it's not my preference; I'd rather avoid this kind of complexity

Should I Do a Mega Backdoor Roth?

Answer a few honest questions about your plan, your finances, and your tolerance for paperwork, and our Decision Guide will tell you whether the mega backdoor Roth is the move for you this year.

Published April 25, 2026

Questions in this guide:

Does your employer's 401(k) plan allow AFTER-TAX contributions beyond the regular $24,500 employee limit?
- Yes — I've confirmed it in my plan documents or with HR
- Probably, but I haven't actually checked
- No — my plan doesn't allow after-tax contributions
Does your plan let you move that after-tax money into a Roth account — via in-service withdrawals to a Roth IRA, or in-plan Roth conversions?
- Yes — and ideally with frequent or automatic conversions
- I think so, but I'm not sure how often it's allowed
- No — neither option is available, or I haven't checked
Are you already maxing both your regular 401(k) AND your Roth IRA (direct or backdoor) every year?
- Yes — both fully maxed
- One of them maxed, the other partial
- Neither is maxed yet
What's the foundation under all this — emergency fund and high-interest debt?
- Solid 3–6 month emergency fund, no high-rate debt
- Mostly there, but a few gaps
- Still building — I have credit card debt or a thin emergency fund
How much extra cash do you have to put toward retirement each year, AFTER maxing your regular 401(k) and Roth IRA?
- $25,000+ — I can fully use the after-tax space
- $5,000–$25,000 — I could do a partial mega backdoor
- Less than $5,000 extra
How does your current tax bracket compare to where you expect to land in retirement?
- Lower now, higher later — locking in Roth at today's rate is a clear win
- About the same
- Higher now, lower later — Roth is less compelling for me
How many years until you plan to retire?
- 30+ years — I'm early in my career
- 10 to 30 years — mid-career
- Less than 10 years — I'm close to the finish line
How comfortable are you with the operational complexity — timing contributions, watching for excess, tracking conversion timing, filing 1099-Rs?
- Comfortable — I'm willing to read plan docs and either DIY or pay a CPA
- I'd figure it out, but it's not my preference
- I'd rather avoid this kind of complexity

The mega backdoor Roth lets a high earner shovel an extra $47,500 (the 2026 IRS Section 415(c) cap of $72,000 minus the $24,500 employee deferral, less any employer match) into Roth accounts each year — but only if your specific 401(k) plan checks two specific boxes: it must allow after-tax contributions beyond the regular Roth/pre-tax limit, AND it must permit either in-service withdrawals to a Roth IRA or in-plan Roth conversions of the after-tax balance. Without both features, the strategy isn't available to you, and that's not negotiable. If your plan does qualify, it's only worth doing after you've already maxed your regular 401(k) ($24,500), maxed your Roth IRA ($7,500 directly or via the regular backdoor Roth), built a real emergency fund, and cleared any high-rate debt — this is a 'maxed everything else' move, not a starting point. The faster your plan converts after-tax dollars to Roth, the better, because earnings that accrue between contribution and conversion become taxable, and the 5-year clock on each conversion still applies if you're under 59½ and may need the money.

Sources

COLA increases for dollar limitations on benefits and contributions — Internal Revenue Service
What is a mega backdoor Roth? — Fidelity
Mega Backdoor Roths: How They Work, Limits — NerdWallet
Mega Backdoor Roth: How It Works and Its Benefits — Empower

Should I Do a Mega Backdoor Roth?

Sources

Related Decision Guides