A third-class medical certificate is a certificate given to a private, recreational or student pilot. This certificate is required to get clearance to fly solo.
A medical certificate is a statement from a physician or other health care provider who is also an FAA-authorized aviation medical examiner. This certificate attests to a result of a physical examination and alerts the pilot to any condition that may prevent him from flying before paying for the lessons.
Medical certificates come in three classes when it comes to flying, according to the Federal Aviation Administration. A first-class medical certificate is for those who are airline transport pilots. Second-class medical certificates are for those who pilot commercial airplanes. Third-class certificates are for private, recreational or student pilots.