To keep your pilot certificate current, the FAA requires a Biennial Flight Review with a Certified Flight Instructor every 24 months.

This review consists of at least one hour of ground instruction and one hour of flight instruction. There is no pass or fail, but additional flight or ground instruction may be required.

Preparation: review the aeronautical knowledge requirements outlined in CFR § 61.56 and revenant regulations in Part 91 of the FAR

During the review, your CFI will guide you through maneuvers and procedures necessary to demonstrate your ability to safely exercise the privileges of your pilot certificate.