The Roth conversion ladder is the cleanest legal path to access traditional 401(k) and IRA money before age 59½ without the 10% early-withdrawal penalty. It's been the workhorse of the FIRE community since the early 2010s, and it still works in 2026 — but the timing matters more this year than usual because of the pending TCJA expiry. Here's the mechanics, the math, and the moves.
What changed in 2026
- TCJA tax cuts expire after Dec 31, 2025 — meaning 2026 brackets are back to higher 2017 levels unless Congress extends. This affects conversion timing.
- The "back-door Roth" remains legal in 2026 — repeated reform proposals haven't passed.
- The 5-year rule is unchanged — each conversion has its own 5-year clock before penalty-free withdrawal.
How the ladder works
Step 1: Roll your 401(k) to a traditional IRA when you separate from your employer (no tax event). Step 2: each year, convert a chunk of the traditional IRA to a Roth IRA. You'll owe ordinary income tax on the converted amount. Step 3: wait 5 years from each conversion. After 5 years, the converted principal (not gains) can be withdrawn penalty-free, regardless of your age. Step 4: living expenses come from converted-and-aged dollars on a 5-year delay; new conversions feed the back of the queue.
The math: converting in low-income years
The ladder optimizes when your post-retirement income is low. Example: you retire at 50 with $1M in a traditional IRA. Your only income is dividends and interest, ~$30k/year. You can convert ~$66k/year and stay in the 22% bracket (in 2026 brackets). At that pace, you convert the whole $1M over 15 years — but you only need 5 years of conversions running before you're drawing penalty-free. Total tax over 15 years: ~$170k on $1M conversions, an effective 17% rate. Without the ladder you'd be paying 22-32% federal tax plus 10% penalty.
The TCJA wrinkle
If TCJA expires at the end of 2025 without renewal, the 22% bracket becomes 25%, and other brackets shift upward by 2-4 percentage points. For retirees mid-ladder, this means converting more in 2025 (final TCJA year) and less in 2026+ if rates rise. Watch the legislation. As of May 2026, the political calculus is unclear — partial extensions are possible.
Step-by-step: starting the ladder in 2026
| Year |
Action |
Why |
| Year 0 |
Roll 401(k) → traditional IRA |
No tax event, sets up access |
| Year 1 |
Convert chunk #1 to Roth |
Tax due on converted amount |
| Year 2 |
Convert chunk #2 to Roth |
Tax due |
| Year 3 |
Convert chunk #3 to Roth |
Tax due |
| Year 4 |
Convert chunk #4 to Roth |
Tax due |
| Year 5 |
Convert chunk #5 to Roth |
Tax due |
| Year 6 |
Withdraw chunk #1 principal penalty-free |
First conversion is now 5+ years aged |
In years 1-5 you live on after-tax savings (taxable brokerage, cash). From year 6 onwards, conversions you made 5 years prior become withdrawable.
Common mistakes to avoid
Forgetting the per-conversion 5-year clock. The clock isn't on "all your Roth money" — it's on each conversion separately.
Not having a bridge fund. You need 5 years of expenses outside retirement accounts to live on while the ladder primes.
Converting too much in one year. Big conversions push you into higher brackets, defeating the math.
Ignoring state taxes. Some states tax conversions differently than the federal. If you can move to a no-income-tax state during conversion years, the savings are big.
Forgetting Medicare premium cliffs. Conversions affect MAGI; if you're 63+, conversions can push you into IRMAA brackets and raise Medicare premiums two years later.
FAQ
Can I convert directly from a 401(k) without rolling to an IRA?
Some 401(k) plans allow in-plan Roth conversions. Most don't. The cleaner path is roll-then-convert.
What about the pro-rata rule?
Affects backdoor Roth contributions, not the conversion ladder itself — as long as your traditional IRA is composed only of pre-tax dollars.
Should I convert in down markets?
Yes — same dollar count of converted shares is more shares when prices are low. Bear markets are conversion gold.
What if Congress changes the rules?
Always possible. The ladder has survived three reform attempts since 2017. Don't assume permanence, but don't avoid using it because of theoretical changes.
Where to go next
For related guides see Solo 401(k) vs SEP IRA in 2026, Mega backdoor Roth guide for 2026, and How to prepare for a recession in 2026.