This study investigates the impact of state-level Worker Adjustment and Retraining Notification (WARN) Acts on advance notice and post-displacement labor market outcomes for U.S. workers from 1993 to 2019. State WARN adoption increases the likelihood of receiving 30+ days of notice by about 4 percentage points. Instrumental variables estimates, supplemented with local average response functions to address weak instruments, show that lengthy notice reduces immediate joblessness by 4 to 7 percentage points. The effects are most pronounced for low-skill workers. Longer term outcomes are less robust. The results indicate that enforceable mandates improve short run transitions, particularly for vulnerable workers.