All states have provisions that prohibit supplying alcohol to underage individuals. States punish these activities as criminal offenses, and anyone who knowingly supplies underage individuals with alcohol is committing a crime—except in a few limited circumstances provided by some state laws, such as in a home environment, or for medicinal purposes.
In Washington State, it is illegal to supply alcohol to individuals under the age of 21, with very few exceptions. This prohibition is outlined in the Revised Code of Washington (RCW) 66.44.270, which makes it a gross misdemeanor to furnish liquor to a minor. The law is strict and those found guilty can face significant fines and jail time. However, Washington law does provide for certain exceptions, such as when alcohol is provided to a minor within a private residence and with the permission of the minor's parent or guardian, or for medicinal purposes if prescribed by a physician. Despite these exceptions, the general rule is that supplying alcohol to minors is a criminal offense in Washington State.