Backdoor Roth vs Mega Backdoor Roth 2027

Compare Backdoor Roth IRA ($7k/yr) vs Mega Backdoor Roth ($46k/yr) 2027 — high earners' best Roth strategies for tax-free retirement.

Backdoor Roth Mechanics

Contribute $7k to NON-deductible Traditional IRA. Convert to Roth same day. No tax (already after-tax). Bypasses Roth income limit ($165k single, $246k joint in 2027).

Mega Backdoor Roth Mechanics

Inside 401k: after-tax contributions ($46k/yr max — fills total 401k limit $69k minus employee + employer $23k+match). In-plan convert to Roth 401k. Requires plan support.

Pro-Rata Rule Gotcha

Backdoor Roth: if you have ANY pre-tax IRA balance, conversion is partially taxable. Roll pre-tax IRA into 401k first to clear path.

Plan Support

Mega Backdoor requires: 1) After-tax 401k contributions allowed. 2) In-service withdrawals OR in-plan Roth conversion. About 30% of plans offer all 3.

Source: irs.gov Publication 590-A, financialsamurai.com mega backdoor. Last updated: May 2026.

Frequently Asked Questions

Is backdoor Roth legal?

Yes. Congress eliminated income limits on conversions (2010). Backdoor Roth tacitly endorsed. Eliminate fear of audit.

What if 401k doesn't allow mega?

Ask HR/benefits to add after-tax bucket. Many plans add it on request. Or change employer to one that offers (Google, Microsoft, etc.).

Tax on conversion?

Only on PRE-tax growth in the IRA before conversion. If you contribute and convert same day, $0 growth = $0 tax. Always convert immediately.