There is no law requiring you work until retirement age. Technically, there is no law requiring you work at all. But, I will assume you have bills to pay and you work to live (or live to work). In the United States, the average retirement age is 65 for men and 63 for women.
The FI/RE Movement or Financial Independence / Retire Early Movement is for individuals who decide to pursue financial independence as early as possible. In this post, I will cover one way to define financial independence, how to calculate your own FI/RE Number, and how to accelerate your roadmap to FI/RE.