What is Unemployment Extension?

Legal Definition
Unemployment extension occurs when regular unemployment benefits are exhausted and extended for additional weeks. Unemployment extensions are created by passing new legislation at the federal level, often referred to as an "unemployment extension bill." This new legislation is introduced and passed during times of high or above average unemployment rates. Unemployment extensions are set during a date range in order to estimate their federal cost. After expiration, the unemployment data is re-evaluated, and new legislation may be proposed and passed to further extend them.
-- Wikipedia