You may work for a company that provides a traditional pension plan. A traditional pension plan pays a fixed amount to qualified participants, or pensioners. The amount is determined by the participant's salary history and years of service. A traditional pension may, or may not, include a cost-of-living adjustment (COLA).

The Pension Benefit Guaranty Corporation (PBGC), a government agency, guarantees traditional pension plans. These traditional pension plans are called defined-benefit retirement plans.

More than likely, your employer uses a defined-contribution retirement plan. Defined-contribution plans rely on how much you and/or your employer contribute during your working years to your own retirement account. You invest your contributions in mutual funds or, in some cases, the stock of your employer. As a result, the size of your retirement account is also determined by the investment performance of those mutual funds and appreciation in your company's share price.

The most common type of defined-contribution retirement plan is a 401(k) plan. If you work for a university or non-profit organization, you may contribute to a 403(b) plan. If you are a state or local government employee, you more than likely participate in a 457 plan. All three of these plans are named after the sections of tax code that govern them.

With defined-contribution plans, your employer deducts a portion of your income, before taxes, and deposits it in your account. Because these are tax-deferred accounts, your contributions grow to a larger amount than if you were to pay income taxes.

As a result of the Economic Growth and Tax Relief and Reconciliation Act of 2001, you can make larger contributions to your 401(k) or other retirement plan beginning in 2003. A catch-up provision allows workers who turn age 50 to make even larger contributions.

Your contributions to a 401(k) or other defined-contribution plan are made to a tax-deferred account. Tax-deferred investments are allowed to compound until you begin to take out money from that account. As a result, they grow to a much larger sum than if you had to pay taxes each year along the way.

The tax advantages of tax-deferred accounts make them a great way to save for your retirement. If your employer has a 401(k) plan or other tax-advantaged retirement plan, it clearly pays to contribute as much as you can afford to every year, and to start as soon as possible. If matching contributions are available -- whether partial or fully matching -- a defined-contribution plan makes even more sense.

The following topics affect the handling of a retirement plan that is sponsored by your employer:

Early withdrawals. If you take out money from your 401(k) plan before you turn age 59-1/2, you will owe income taxes on the amount of the withdrawal. More than likely, you will also have to pay an early-withdrawal penalty of 10% on the amount. There are very few exceptions to the 10% penalty.

Required minimum distributions. The IRS requires you to begin taking distributions every year after you turn 70-1/2. These are called required minimum distributions. However, accounts administered under qualified Roth contribution programs (which the tax law authorizes beginning in 2006) do not require RMDs. RMDs are also called MRDs.

Rollovers. If you leave your employer or retire, you can move your 401(k) plan assets to an IRA or retirement plan of another employer. This process of moving your retirement plan is called a rollover. Be sure to handle a rollover carefully so that you avoid any early-withdrawal penalties or income taxes.

The above information is educational and should not be interpreted as financial advice. For advice that is specific to your circumstances, you should consult a financial or tax adviser.