The purpose of the labor certification required in employment-based immigration is to protect U.S. workers by requiring employers to seek a U.S. worker before hiring a foreign one.  However, sometimes it is in the national interest to hire a foreign national with special qualifications, rather than a minimally qualified U.S. worker.  National interest waivers waive the labor certification requirement for such foreign

In order to qualify for a national interest waiver, you must show: (1) you are seeking employment in an area of “substantial intrinsic merit”, (2) your employment will benefit the U.S. to a “substantially greater degree” than would employing a U.S. worker, and (3) the benefit in hiring you outweighs the interest in protecting U.S. workers as intended by the labor certification process.  Typically, national interest waivers are granted for scientists, doctors, and similar professions, but they are available for other professions as well.