Roth vs. Traditional IRA: Maximizing Retirement Tax Arbitrage

Choosing between a Traditional and a Roth retirement account is one of the most critical decisions for US wealth builders. The correct choice depends entirely on **tax bracket arbitrage**—comparing your tax rate today with your expected tax rate in retirement.

The Rule of Thumb

• Traditional IRA (Pre-Tax): Better if your marginal tax rate *now* is higher than it will be in retirement. You save tax today at your highest rate, and pay tax in retirement at a lower average rate.
• Roth IRA (Post-Tax): Better if your marginal tax rate *now* is lower than it will be in retirement. You pay low taxes today, and withdraw all contributions and gains 100% tax-free later.