Can you retire at the age of 50?

In the United States, ever since the 13th amendment to the Constitution was ratified, you can retire at any age you want.

However, you will not be able to collect Social Security at that age (unless you are disabled). Withdrawals from an IRA or 401k will be penalized unless part of a SEPP plan. Whether you will be able to collect payments under a defined benefit plan will depend on the terms specified in the plan documents.