The Roth conversion ladder: tax-free access to retirement money before 59½

• Year 1: roll your old 401(k) into a traditional IRA, then convert a year's worth of spending (say $50,000) to a Roth IRA. Pay ordinary income tax on it.
• Years 2–5: convert another rung each year. Live on taxable savings, Roth contributions, or other income while the clocks run.
• Year 6: the Year-1 conversion principal is now withdrawable tax- and penalty-free, at any age. Each later rung matures on its own five-year anniversary.
• Ongoing: the ladder keeps rolling until 59½, when all retirement money becomes accessible anyway.

The ladder shines because early retirement years are usually low-income years: a household that retired at 45 with no wages can convert tens of thousands of dollars a year at the standard deduction and 10–12% brackets — rates they may never see again. That's the same 'golden window' logic as pre-RMD conversions, stretched over more years.

The trade-off is subsidy interaction: conversion income counts toward ACA marketplace subsidies, so each rung raises health-insurance costs during exactly the years you're buying your own coverage. For many early retirees the optimal rung size is set by the ACA math, not the tax brackets.

The classic failures: starting the ladder without five years of bridge money (forcing penalized withdrawals anyway); confusing the per-conversion five-year clock with the separate five-year rule on Roth earnings; and converting so much in one year that the tax and lost subsidies outweigh the penalty being avoided. A 72(t) SEPP schedule is sometimes the better tool — it starts paying immediately — at the cost of rigidity. Model both against your actual bridge assets before committing.