Washington Initiative 502 (I-502) "on marijuana reform" was an initiative to the Washington State Legislature, which appeared on the November 2012 general ballot, passing by a margin of approximately 56 to 44 percent. Originally submitted to the Washington Secretary of State during the summer of 2011, enough signatures were collected and submitted by December to meet the required 241,153 signatures, sending it to the legislature. When the legislature adjourned without action in April, Initiative 502 automatically advanced to the November 2012 general ballot. It was approved by popular vote on November 6, and took effect over the course of a year, beginning with certification no later than December 6, 2012. Along with a similar Colorado measure, Initiative 502 was credited for encouraging voter turnout of 81%, the highest in the nation.
Initiative 502 defined and legalized small amounts of marijuana-related products for adults 21 and over, taxes them and designates the revenue for healthcare and substance-abuse prevention and education. As noted at RCW 69.50.101, cannabis is still classified as a schedule I controlled substance under federal law and subject to federal prosecution under the doctrine of dual sovereignty. Possession by anyone younger than 21, possession of larger amounts, and the growing of unlicensed or unregulated marijuana remains illegal under state law.