It's been around since 1998. But you have only another week to take advantage of it for 2007 -- and the savings are too good to miss.

The Roth IRA celebrates its 10th anniversary this year, and plenty of investors have taken advantage of its unique characteristics to help them save for retirement. Although the amount of money in traditional IRA and 401(k) plans still dwarfs what people have in Roth IRAs, Roth IRAs enjoy something those other plans can't offer: completely tax-free growth.

A novel concept
Back then, the whole idea behind the Roth IRA was completely new. There were plenty of different ways the tax laws allowed people to save for retirement, but they were all based on the concept of deferred compensation -- you set money aside during one year for use in a later year. For tax purposes, the laws followed that concept, too. The benefit was that you wouldn't have to pay tax in the year you set aside the money; instead, you deferred the tax until the year you actually used it.

There's no denying that tax deferral is a valuable benefit in retirement saving. The Roth IRA, however, went one step better by providing tax elimination. Granted, it comes at a cost: You don't get the valuable tax deduction that so many IRA and 401(k) participants count on. But by giving up that one-time benefit, you earn a lifetime exemption from taxes on that money.

10 years old and looking good
After 10 years, investors are starting to see some of the benefits of tax-free treatment for Roth IRAs. Back in 1998, you could contribute only $2,000 a year to your Roth IRA. But as you can see below, a decade of investment could have turned that $2,000 into a lot more.

Stock

$2,000 in 1998 Is Now Worth

Potential Tax Avoided

Amazon.com (NASDAQ:AMZN)

$19,471

$6,815

Apple (NASDAQ:AAPL)

$47,688

$16,691

Genentech (NYSE:DNA)

$18,025

$6,309

Johnson & Johnson (NYSE:JNJ)

$4,242

$1,485

PepsiCo (NYSE:PEP)

$3,979

$1,393

Potash (NYSE:POT)

$28,457

$9,960

And that's just the tip of the iceberg. Unlike traditional IRAs, Roth IRAs don't ever force you to start taking withdrawals, no matter how old you are. That means that it's entirely up to you how much you take -- and how much you leave to grow inside your Roth IRA, for decades to come.

Double your fun
If you haven't made a Roth IRA contribution for 2007 yet, you can still do so -- but only for another week. After the April 15 tax filing deadline, your chance to make a contribution for last year will end. For 2007, you can contribute up to $4,000 -- twice the original amount in 1998 -- to a Roth. In 2008 and subsequent years, that limit goes up to $5,000, further multiplying the potential savings. And if you're 50 or older, you can add another $1,000 on top of the limits for both years.

So don't let another year go by without capitalizing on a great way to save toward retirement. In just a decade, the Roth IRA has revolutionized retirement savings -- and with everything the Roth has going for it, you can't afford to lose another opportunity.

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