Psilocybin mushrooms are not specifically named in the U.S. federal scheduling system, however their two primary active chemicals Psilocybin and Psilocin are both Schedule I in the United States. This makes them illegal to buy, sell, or possess without a DEA license. Fresh and dried psilocybin mushrooms are considered containers of Psilocybin and Psilocin making them illegal to possess. Because mushroom spores contain no psilocybin or psilocin, they are legal to sell and possess in all states except California, Georgia and Idaho. Federal law prohibits cultivating shroom spores all states.
Psilocybin spore syringes are legal to sell and possess in every state except California, Georgia, and Idaho. Posession of fully grown magic mushrooms is illegal in every state in the United States except Florida. Florida stands out because of a decision in 1978 in Fiske v Florida by the Florida Supreme Court which ruled that wild-picked magic mushrooms could not be legally considered "containers" of psilocybin and thus would have to be specifically listed in Florida law by the legislature if they meant to make them illegal. Since the Florida legislature has not chosen to change the laws since then, wild Psilocybin mushrooms are presumptively legal to possess in Florida. This does not mean police won't arrest people for possession of even wild mushrooms, but this has been used as a successful defense against such charges.