Why do FIRE planners build a taxable brokerage 'bridge' account?

A taxable brokerage account has no age restrictions — you can sell shares at 40 just as easily as at 70 — which makes it the natural bridge between early retirement and the day penalty-free retirement-account access opens up. Unlike a 401(k) or IRA, there's no 10% early-withdrawal penalty, and long-term capital gains are often taxed at favorable rates (0%, 15%, or 20% depending on income). Many people FIRE'ing aim to hold roughly five-plus years of expenses in taxable funds so they can live on it while a Roth conversion ladder seasons. It also gives you control over your taxable income each year, which matters for ACA subsidies and 0% capital-gains harvesting. The tradeoff is you lose the upfront 401(k)/IRA deduction, so most people max tax-advantaged accounts first, then funnel surplus savings here. Model the bridge size at wealthserene.com/tools/fire-calculator.