In the United States, cannabis-related laws are evolving regularly. Technically, CBD is still considered a Schedule I drug under federal law.
Hemp has been removed from the Controlled Substances Act, but the Drug Enforcement Administration (DEA) and Food and Drug Administration (FDA) still classify CBD as a Schedule I drug.
However, 33 states plus Washington, D.C., have passed cannabis-related laws, making medical cannabis with high levels of THC legal. The cannabis may need to be prescribed by a licensed physician.
In addition, several states have made recreational use of cannabis and THC legal.
In states where cannabis is legal for recreational or medical purposes, you should be able to buy CBD.