The Patent Bar is the examination required to practice before the United States Patent and Trademark Office (USPTO) as a patent attorney or patent agent. The General Requirement Bulletin for Admission to the Patent Bar lists the necessary requirements to register for and pass this examination.
An important thing to note is that a law degree is not required before taking the Patent Bar nor is it required to be a patent practitioner. Those who pass the Patent Bar without a law degree become a registered Patent Agent. Patent Agents can represent clients before the patent office, but only Patent Attorneys (individuals who have passed the Patent Bar and who have a law degree) may represent clients in contracts and licensing or in court, arbitration, or other adversarial proceedings. Thus, if you are interested in taking the Patent Bar, you can do so at any point; you do not have to wait until after you graduate law school.
The Patent Bar is offered year-round via computer at test centers across the country and on a date and time chosen by the applicant. There is no paper examination offered. Applicants who take the computer-delivered examination will receive an unofficial result at the end of the examination on the computer on which they take the examination.