Can a lawyer from another country practice in the US?

Not unless they become members of the bar in the appropriate state. Each state sets up the requirements to practice law in their state, and it varies, but in general: Complete a law degree (There are a few states that do not require that) Take and pass the Professional Responsibility Exam Submit a completed application that includes citizenship, fingerprint checks, background investigations and criminal record check. Take and pass the State Bar Exam. You can apply to transfer your membership from one state to another and some states will allow this, others will not. (Florida does not, too many retired attorneys wanting to retire there.)