401K plan

Asalamualaikum wa rahmatullah
Most of the companies in the United State offer a retirement plan to their employee which is called 401K plan. In this plan, the employee puts aside some money in every pay check and that money is invested in US Stock, Non-US Stock, Bonds, Cash and others. The money you invested increases or decreased based on the market/stock market situation. We cannot take this money out until we retire which is set as 65 years.
Please let me know if we have to pay zakat on this money?