Kratom (Mitragyna speciosa) is uncontrolled in the United States with the exception of of laws passed in Alabama, Arkansas, Indiana, Rhode Island, Tennessee and Vermont, Washington D.C. and Wisconsin. Kratom is legal in all other states.
This means that all parts of the plant and its extracts are legal to cultivate, buy, possess, and distribute (sell, trade or give) without a license or prescription. If sold as a supplement, sales must conform to U.S. supplement laws. If sold for consumption as a food or drug, sales are regulated by the FDA.
In 2012 Indiana banned the chemicals Mirtagynine and 7-hydroxymitragynine, but the legal definition does not appear to cover the plant Kratom. In 2012, Vermont issued a an emergency order to ban several new designer chemicals which included 7-hydroxymitragynine (one of the active alkaloids in Kratom), effectively banning Kratom in Vermont.
Laws change quite often and ignorance of the law does not excuse criminal conduct (Ignorantia juris non excusat)., so be sure that Kratom is legal where you live before using it.
The updated map below, provided by Kratom.la, shows a visual representation of the legal status of Kratom throughout the United States.
Green: States is where Kratom (Mitragyna speciosa) is legal.
Light Green: States have been legally amended to save Kratom.
Red: States is where Kratom is currently not legal.