From ANA's Workplace Advocacy Program:
As a registered nurse, you maintain professional standards of practice. But this does not mean that you must work extra hours without appropriate compensation.
Under the Fair Labor Standards Act (FLSA)--the federal law that governs wages and hours of work--you are entitled to fair compensation for the work you do whether you are paid a salary or by the hour.
Contents:
Who is paid overtime?
When can you receive overtime?
Who doesn't get overtime?
What if your paycheck is incorrect?
http://www.ana.org/dlwa/wages/wp4.htm