Withdrawing from a 401(k), IRA, or similar retirement account before age 59½ usually incurs income tax plus a 10% early withdrawal penalty, totaling around 32% for someone in the 22% tax bracket, plus state taxes. Exceptions to the penalty are limited, including disability, death, medical expenses, and first-time home purchases. Employer plans have additional exceptions. Alternatives include 401(k) loans, Roth IRA contributions, or using taxable accounts first.