The following states have passed laws decriminalizing certain marijuana possession offenses. Typically, decriminalization means no arrest, prison time, or criminal record for the first-time possession of a small amount of marijuana for personal consumption. In most decriminalized states, these offenses are treated like a minor traffic violation.
* Voters in each of these jurisdictions have subsequently approved legislation legalizing the adult use and personal cultivation of cannabis
** Delaware’s decriminalization law takes effect December 18, 2015
*** Missouri’s decriminalization law takes effect January 1, 2017.
**** These states still classify marijuana possession offenses as criminal misdemeanors, but the offenses do not carry any threat of jail time.
Source – http://norml.org/