How is Lean FIRE different from regular FIRE, and what are its risks?

Lean FIRE means reaching financial independence on a deliberately minimal budget, often under about $40,000 a year for a household, which lets you hit a smaller number sooner. A Lean FIRE portfolio might be $600,000 to $1 million rather than the $1.5 million-plus a more typical plan needs.

The appeal is speed and freedom; the risk is fragility. With little discretionary spending, a surprise expense, a healthcare shock, or higher-than-expected inflation leaves less room to absorb the blow. Lean retirees often keep skills sharp for part-time income and lean heavily on geographic arbitrage or paid-off housing. It works best for adaptable people comfortable with a simple lifestyle, but it demands a stronger backup plan than a more cushioned approach.