The Roth Conversion Ladder, Modeled Honestly

The most-cited strategy in early retirement is also the most hand-waved. Here are the actual IRS rules, what a real ladder schedule looks like, and the penalty math when you get it wrong.

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If you've spent any time in FIRE forums, you know the pitch: your 401(k) isn't locked until 59½, because you can roll it to a traditional IRA, convert a slice to Roth each year, wait five years, and spend it penalty-free. It's true. It works. Thousands of people are living on ladders right now.

What's usually missing is precision. Which five years? Five years from when, exactly? What happens if you tap a rung early? How do conversions you made before retiring fit in? The details are where ladders succeed or fail, so let's do the details.

The Rules That Make It Work

Two pieces of the tax code combine into the ladder.

First, the IRS ordering rules (§408A(d)(4)). Every distribution from your Roth IRAs — the IRS treats them as one pool — comes out in a fixed order, regardless of which account you pull from:

1. Regular contributions — always tax-free and penalty-free, at any age, full stop.
2. Conversion principal — oldest conversion first (FIFO), and within a conversion, the taxable portion first.
3. Earnings — taxable plus a 10% penalty if you're under 59½.

You cannot choose to withdraw earnings first. The ordering is mandatory, and it's what makes the ladder deterministic.

Second, the conversion five-year clock. Each conversion starts its own clock on January 1 of the year of the conversion — not the anniversary of the transaction. Convert in December 2027 and that money is seasoned on January 1, 2032: barely more than four calendar years. Withdraw converted principal before its clock matures and before age 59½, and you owe a 10% "recapture" penalty on the amount — the early-withdrawal penalty you skipped at conversion time. No income tax, though; that was already paid when you converted.

Both clocks stop mattering at 59½. Once you attain it, conversion principal is penalty-free regardless of age of the rung.

What a Real Ladder Looks Like

Say you retire at 45 needing $60,000 a year, with a large traditional IRA plus enough taxable brokerage and existing Roth contributions to cover about five years. The shape (dollars simplified — in practice each year's conversion grows with your spending):

This is why the summary is "convert one year of spending, five years ahead." The ladder needs a five-year runway of non-ladder money — taxable accounts, Roth contribution basis, cash — before the first rung matures. If you converted before retiring, even better: a 2024 conversion is spendable in 2029, so part of your runway may already be built. Prior conversions carry real, already-running clocks.

Three details people miss:

• Conversions are ordinary income, so each rung fills tax brackets — and, if you're buying ACA coverage, counts toward the subsidy math. The ladder and the ACA bridge compete for the same MAGI room.
• Pay the conversion tax from taxable money. If you have tax withheld from the conversion itself before 59½, the withheld amount never reaches the Roth — it's a straight early withdrawal, taxed and penalized.
• The clocks are per conversion. Five conversions means five independent clocks. There's no blending.

The Penalty Math When You Get It Wrong

Suppose you convert $50,000 in 2027 and your plan slips — a roof, a market drawdown, optimism — and you pull that $50,000 in 2031 at age 49. The clock needed January 1, 2032. You owe 10% recapture: $5,000, on money you already paid income tax on four years earlier. Pull it in January 2032 instead and you owe nothing. The difference between those two outcomes is one month of patience and a plan that tracked the right date.

Dig past a rung into earnings and it's worse: earnings drawn before 59½ are ordinary income plus the 10% penalty. A ladder that's one year short doesn't fail gracefully — it fails at your marginal rate plus ten points.

How retireclarity Models This

The projection engine implements the ordering rules directly. Every Roth withdrawal in a projection is decomposed the way the IRS would: contribution basis first (set "Contributions to date" on your Roth accounts), then conversion layers oldest-first, then earnings. Each in-projection conversion becomes a layer with its own clock, seasoning at conversion year + 5 — or immediately once its owner attains the penalty-free age, whichever comes first. Draws consume layers FIFO; unseasoned draws incur the 10% recapture; non-qualified earnings draws incur income tax plus penalty. For couples, seasoning is tracked per owner: a younger spouse's conversion layers stay recapture-exposed even after the older spouse clears 59½.

That means you can build a ladder in the app and watch it hold or break: set conversions on the Roth Conversion Optimizer (the optimizer measures a curve of schedules and the How much to convert slider picks your point on it, from converting nothing to the Max schedule), retire before 59½, and the projection will price any year where spending outruns seasoned money.

Simplifications to know about, from the Modeling Notes:

• Conversions made before today aren't seeded into the ladder. Only in-projection conversions get clocks. If you leave contribution basis blank, the app's default treats your entire starting Roth balance as basis — lenient for past conversions still inside their five years. If you do enter basis, pre-existing conversions fall through to the earnings tier — harsher than reality. Seeding real prior-conversion clocks is a planned follow-up.
• Roth money is one household bucket. Per-account five-year clocks and Roth-401(k) pro-rata rules aren't modeled; earnings qualification uses the older living spouse's age.
• The 59½ convention is annual. The whole calendar year in which someone attains 59½ is treated as penalty-free — mildly lenient, matching the engine's mid-year withdrawal convention.
• The optimizer doesn't yet optimize for the ladder. It maximizes your after-tax estate (pricing brackets, IRMAA, and ACA subsidies through the real projection); it doesn't yet target penalty-free early access as an objective. Ladder-aware optimization is on the roadmap — today you shape the ladder yourself and let the engine referee it.

The ladder is real, legal, and well-documented. It is also unforgiving of arithmetic errors measured in months. Model it with the actual clocks — yours or ours — before you rely on it. The Roth conversion calculator is the fastest way to see a ladder priced against real balances.

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Related Articles

• The ACA Bridge: Health Insurance from Early Retirement to Medicare — Why every ladder rung also counts against your health insurance subsidy.
• 72(t) SEPP: The Early-Access Tool of Last Resort — What to use when you need traditional money now, not in five years.
• Roth Conversions: When They Make Sense (And When They Don't) — The tax-arbitrage case for conversions, separate from early access.

From the Guide: Retiring Before 59½ · Roth Conversions · Modeling Notes