If you work for an employer who sponsors a retirement savings plan, you can invest for the future and enjoy the advantage of tax-deferred earnings at the same time.
Sometimes you must take the initiative to enroll in the plan, but in other cases you may be automatically enrolled. In that case, you do have the right to opt out — though agreeing to participate is one of the smartest decisions you can make.
Retirement savings plans, including 401(k)s, 403(b)s, 457 plans, and SIMPLEs, are defined contribution plans. That makes them different from traditional pensions, also called defined benefit plans, where the employer is responsible for paying retired workers a fixed amount of annual income. In a defined contribution plan, the retirement income you receive is based on the amount that was contributed to your account during your working life, how those contributions were invested, and the return the investments provided.
Defined benefit or defined contribution?
In a defined benefit plan, money that your employer puts into the plan account is in addition to whatever you earn for the work you do. In most defined contribution plans, at least some of the money that’s set aside for the future reduces your take-home pay.
If you work for an employer who sponsors a 
