The conduct of attorneys is governed by rules of ethics and professional responsibility. The Model Rules of Professional Conduct has been published by the American Bar Association since 1983, with several amended versions over the years. It was preceded by the Model Code of Professional Responsibility. The Model Rules set forth professional standards governing the practice of law. Most states have adopted the Model Rules, though some with modifications. California is currently the only state that has not adopted some version of the Model Rules.
The Model Code of Professional Responsibility was created by the American Bar Association in 1969. It was replaced by the Model Rules of Professional Conduct in 1983. The Model Code consisted of Canons of Professional Ethics, Ethical Considerations, and Disciplinary Rules. Only the Disciplinary Rules were mandatory. New York was the last state to still follow the Disciplinary Rules, but in April 2009 New York changed over to the Rules of Professional Conduct.