Roth conversion ladder.
The early retiree's best friend.

What a Roth conversion is

A Roth conversion is moving pre-tax money (Traditional IRA or 401(k)) into a Roth IRA. The converted amount is added to your taxable income for that year and taxed at ordinary rates. From then on, it grows tax-free and comes out tax-free in qualified withdrawals.

There is no limit on how much you can convert in a year. It is not a contribution. You are not using up your $7,500 Roth contribution cap. You can convert $5,000 or $500,000. The only cost is the tax bill, which you should pay from outside the conversion (from taxable savings) to maximize the move.

Why you'd do it

• Fill lower tax brackets in low-income years. If you stopped working in July and your taxable income is $40K instead of your usual $150K, you have a huge "hole" in the 12% bracket. Fill it with a conversion at 12% instead of waiting to withdraw it at 22% or 24% later.
• Lock in current tax rates. If you expect tax rates higher later (plausible given federal deficits), pay now.
• Reduce future RMDs. Traditional balances get hit with Required Minimum Distributions starting at 73. Big pre-tax balances produce large forced taxable income. Roth IRAs have no RMDs, ever.
• Leave tax-free inheritance. Heirs pay zero federal income tax on inherited Roth withdrawals. Traditional IRA heirs pay ordinary income on every dollar over 10 years.

The optimal window

Three types of years are gold:

• Early retirement (before age 73). Between the day you retire and the day RMDs and Social Security fully kick in, your taxable income can be very low. This is the canonical conversion window.
• Low-income gap years. Gap between jobs, sabbatical, grad school, parental leave, self-employed slump year. Any year your income dips well below your norm is a conversion opportunity.
• Market downturns. Convert a depreciated position when prices are down. You pay tax on the lower value. The recovery happens tax-free in the Roth.

The Roth conversion ladder for early retirees

Step by step, for a 50-year-old retiring with $1M in a 401(k).

1. Roll the 401(k) to a Traditional IRA at Fidelity, Schwab, or Vanguard.
2. Each January, convert ~$50,000 from the Traditional IRA to a Roth IRA. Pay federal tax on the $50K at the time of filing.
3. The converted $50K must season in the Roth for 5 years before the principal becomes accessible penalty-free.
4. Starting in year 6, that first $50K is withdrawable penalty-free even though you are under 59.5. Each subsequent year unlocks the next seasoned batch.
5. Between ages 50 and 75, with modest growth on the remaining balance, you have converted 25 x $50K = $1.25M at an average effective tax rateeffective tax rateYour actual average tax rate, total tax paid divided by total income. Always lower than your marginal rate.Full definition of ~10-12%, instead of letting it sit and producing RMDs at 22%+ later.

The ladder solves two problems at once: it funds early retirement tax-efficiently, and it decompresses the RMD bomb at 75.

How Bitcoin volatility creates conversion opportunities

Suppose you hold 10 BTCBitcoin (BTC)The ticker symbol for Bitcoin, used on exchanges and in price quotes.Full definition inside a Traditional IRA (via IBIT or FBTC). BTC sits at $100,000 per coin. Position value: $1M. Converting the whole thing would mean $1M of taxable income - brutal.

Now BTC has a 70% drawdown. Your position is worth $300K. You convert the whole thing. Taxable income: $300K. Tax bill: maybe $70-80K in a reasonable bracket.

BTC recovers and more than triples from the low back to $100K. That recovery happens entirely inside the Roth - tax-free. You effectively paid tax on $300K to move $1M of future value.

IRMAA cliff awareness

Medicare Part B and D premiums get expensive above certain income thresholds. This is the Income-Related Monthly Adjustment Amount (IRMAAIncome-Related Monthly Adjustment Amount (IRMAA)A Medicare surcharge added to your monthly premium if your income exceeds certain thresholds.Full definition). Conversions add to Modified Adjusted Gross Incomegross incomeYour total income before any taxes or deductions are subtracted. (MAGIModified Adjusted Gross Income (MAGI)Your taxable income with certain deductions added back in. The IRS uses this slightly different number to decide if you qualify for some tax breaks.Full definition) and can push you over a cliff.

For 2026, the first IRMAA cliff is roughly $109,000 MAGI for single filers and $218,000 for married filing jointly. Crossing even by $1 triggers surcharges ranging from $96 to $578 per month per spouse. The surcharge is based on MAGI from two years prior, so a big conversion in 2026 affects 2028 Medicare premiums.

If you are 63+ and approaching Medicare eligibility, run an IRMAA-aware model before converting. Sometimes converting a bit less to stay under a cliff is worth more than the marginal tax arbitragearbitrageProfiting from price differences in the same asset across different markets, often by buying low in one place and selling high in another..

Timing and mechanics

Conversions can happen any time in the calendar year. There is no once-per-year limit, and a direct conversion has no 60-day rollover rule. You can convert multiple times, and you can choose which specific assets to move (convert your BTC lot when it is down, leave your bond lot alone).

December is a common time: you know your year's income roughly, and you can size the conversion to exactly fill the target bracket. But waiting until December means missing the benefit of a mid-year market crash. A good rule: convert opportunistically when depressed assets are available, then top up in December.