Using high-quality Finnish register data and a regression discontinuity approach, we study the health effects of reaching the legal drinking ages of 18 and 20. Our results show that at age 18, when beer, wine, and car driving become legal, mortality and hospitalizations increase discontinuously, especially among men, and they are driven by alcohol and traffic-related causes. At age 20, when spirits become legal, alcohol-related deaths and accidents increase for men, and suicide risk rises for women. We also find meaningful adverse spillover effects on younger siblings. When an older sibling turns 18, their younger brothers face increases in alcohol-related mortality, traffic-related hospitalizations, and suicide attempts, while younger sisters experience more alcohol-related hospitalizations. Spillovers at age 20 are weaker but persist for younger brothers.