Initiative 1639 was a Washington state ballot initiative concerning firearms regulation that was passed into law on November 6, 2018. The initiative altered the gun laws in Washington by defining the term "semiautomatic assault rifle" to include all semiautomatic rifles,[1][2] raising the minimum age for purchasing semiautomatic rifles from 18 to 21. It also imposes a 10-day waiting period before being allowed to claim a rifle from a firearms dealer, and expanded background checks to include medical records requiring a waiver of HIPAA rights.[3]