Like physicians who have passed the medical boards or lawyers who have passed the bar exam, professional engineers have fulfilled the education and experience requirements and passed the rigorous exams that, under state licensure laws, permit them to offer engineering services directly to the public. Professional engineers are bound by a code of ethics to hold paramount the safety, health and welfare of the public and to act truthfully, honorably and lawfully to perform services within their specific area of expertise.

Engineering licensure laws vary from state to state but, in general, to become a professional engineer an individual must be a graduate of an engineering program approved by the Accreditation Board for Engineering and Technology, pass the non-disciplined Fundamentals of Engineering exam, practice under the direction of a professional engineer for an intern period of four years and pass the disciplined Principles and Practice of Engineering exam administered by the state Board of Engineering Examiners.

A state licensing board regulates the practice of engineering within each state. The National Society of Professional Engineers, in conjunction with its state chapters, represents the interests of professional engineers nationwide. A licensed professional engineer appends the initials PE to his or her name.