The Federal government and many state governments maintain lists of vendors with whom, because of various transgressions, they will no longer do business. A best practice one should adopt is to check available debarment/suspension lists before awarding a contract or making a purchase. The two links below will redirect you to Federal debarment lists. Clicking on the map below will redirect you to a specific state's debarment/suspension listings if they are available.
Click on any state to see a listing of debarred vendors in that state. Not all states maintain debarrment lists.