A 401(k) can be one of your best tools for creating a secure retirement. It provides you with two important advantages. First, all contributions and earnings to your 401(k) are tax deferred. You only pay taxes on contributions and earnings when the money is withdrawn. Second, many employers provide matching contributions to your 401(k) account which can range from 0% to 100% of your contributions. The combined result is a retirement savings plan you can not afford to pass up.