NEW YORK (MONEY Magazine) - It's easy to feel anxious about your retirement. Even if you've been saving for years, it's natural to wonder if you've made the right decisions.

And if you haven't begun saving yet, well, the fear that you're starting too late can be daunting enough to keep you from getting in the game at all. But that's a mistake.

Sure, there are many questions (Am I saving enough? Am I adequately diversified? Do I have the best investments?). It can all seem overwhelming -- and, therefore, well worth avoiding. Most of us lead frantically busy lives anyway, so tending a portfolio can easily slip down the to-do list.

What's more, when you have a jumble of investments -- 401(k)s from two or three jobs, assorted IRAs, maybe an online brokerage account -- simply keeping track of it all can turn into a time-consuming pain in the neck.

Relax. There is a better way. MONEY has created a simple system for getting your retirement on track, using principles you can learn in just 15 minutes. Our plan includes no detailed calculations of future living costs, or worksheets for locating every penny of your net worth.

But that doesn't mean this program isn't sophisticated. Basically, we've done the heavy lifting and distilled retirement planning into a flexible system that can grow with you.

Best of all: Once you put our plan into action, you need to do very little -- about 15 minutes' worth of work a year -- to maintain it. And that will liberate lots of time to, say, play with your kids or figure out your next vacation. So let's get to it.

Most retirement planners have you start by calculating how much you'll need to retire comfortably. But even the most meticulously plotted target isn't particularly meaningful unless you plan to stop working fairly soon. Beyond five to 10 years, the future is essentially unknowable. None of us can accurately predict what our lifestyle, taxes or health benefits will cost, or what our investments will earn. We don't even know what we'll earn down the road.

What's more, the huge numbers that retirement calculators tend to spit out (got a couple million bucks hanging around?) may do little more than discourage you from getting started.

You can't control the future, but the present is in your hands. Your first step is to get into the habit of saving, so your money has more time to work for you.

One recent study claims we need to save up to 17 percent of our income for retirement. Don't let that scare you. Any savings, however modest, will help.

We'd start by putting at least 5 percent of your income into a tax-deferred retirement plan -- be it a 401(k), 403(b) or 457. If your employer matches your contribution, make sure to save enough to qualify for the entire match. Wherever you start, you can gradually work your way up.

"We tell people to save what they're comfortable with, but raise it by 1 to 2 percent [of their salary] every year," says Steve Utkus, director of the Vanguard Center for Retirement Research. "It's these small, incremental changes that get you where you want to go."

Want proof? Professors Shlomo Benartzi of UCLA and Richard Thaler of the University of Chicago devised a savings program based on this idea called Save More Tomorrow (SMarT), which is now being adopted by 401(k) providers such as Vanguard.

Under the program, workers agree to boost their 401(k) contributions automatically by two to three percentage points with each annual raise until they hit their company's max.

During a four-year test of the SMarT plan at a mid-size corporation, participants' average savings rates jumped from 3.5 percent of their pretax pay to 13.6 percent. Powerful stuff.

The easiest way to stick with a savings plan is to make it automatic, and that's why your 401(k), 403(b) or 457 should be the centerpiece of your retirement. Your employer takes the money out of your paycheck before you can spend it (or pay taxes on it), so you save regularly without even trying.

If you don't have a workplace savings plan -- or you can save more than your plan allows -- set up an automatic investment program with a fund company, bank or brokerage. A phone call, a simple form and a voided check are all it takes for you to have money debited from your bank account every month and deposited in a mutual fund.

Automatic investing not only ensures that you will save consistently, it also makes you a better investor. If you invest regularly (a technique called dollar-cost averaging), you wind up buying more shares when the price is low.

What's more, setting up an automatic investing plan often lets you open a fund account with much less money -- as little as $100 a month -- than if you started with a lump sum.

When you open an account, take advantage of whatever tax breaks you qualify for. Even if your IRA deposits are not deductible, for instance, the money gets the oomph of growing tax deferred.

If you qualify for a Roth IRA (joint filers with incomes below $150,000, singles below $95,000, can put in the full $3,000 a year), your money grows completely tax-free. If you're self-employed, you can save the lesser of $40,000 or 25 percent of your income in a simplified employee pension plan, or SEP-IRA.

If you're over 50, take advantage of IRA and 401(k) catch-up provisions that allow you to put away more money -- $500 more in IRAs in 2004 and 2005.

Many financial advisers and retirement Web sites will try to wow you with their "optimizers" -- software programs that direct exactly how much of your savings should go into different asset classes.

Don't be intimidated. Truth is, building a well-diversified portfolio is a lot easier than that. Simply put 60 percent of your money in stocks and 40 percent in bonds. Stocks promise long-term growth, and bonds provide ballast. You don't need to change that mix until you're about ready to retire.

If you can stomach more risk, a larger dollop of stocks is perfectly okay, especially if you're under 50. But we'd be wary about encouraging even young savers to put more than 80 percent in stocks. By the way, count the cash in your retirement accounts as part of your bond portfolio.

To get a 60-40 stock and bond mix, all you need are two broadly diversified index funds: Vanguard Total Stock Market (800-851-4999) or Fidelity Spartan Total Market Index (800-343-3548) for the stock portion and Vanguard Total Bond Market for bonds. Why index funds? With stocks expected to return an average of 7 to 8 percent a year over the next decade, you must minimize costs, and index funds are among the least expensive on the market.

If your retirement plan does not offer index funds, a well-diversified stock fund such as Fidelity Large Cap Stock or Growth Fund of America (800-421-0180) can fit the stock-index slot; Pimco Total Return (800-426-0107) will give you a broad exposure to bonds.

If managing two funds is still more than you want to deal with, you can go even simpler with a life-cycle fund. These funds hold both stocks and bonds, and reduce your stock exposure as you near retirement. Vanguard Target Retirement funds (800-851-4999), Fidelity Freedom funds (800-343-3548) and T. Rowe Price Retirement funds (800-638-5660) all let you choose from several target dates.

Even a simple strategy requires periodic maintenance. But we've distilled that job to three easy steps.

• Rebalance. Once you create a 60-40 stock and bond mix, your only other job is to check those numbers once a year. If your allocation is less than five to 10 percentage points out of whack, you can wait to make changes. But if, say, the stocks take off and grow to 75 percent of your portfolio, sell enough to bring the stake back to 60 percent and put the proceeds in bonds. This guarantees that you'll buy low and sell high. Plus, in a tax-sheltered plan, you won't owe taxes on those gains.
• Squeeze out more savings. Staying on track means finding more money to save every year. But that doesn't mean denying yourself. Instead, keep tabs on where your money is going and make sure you're getting what you expect from your splurges.
• Check your debt load. If you're having trouble finding enough money to save, check to see if your credit-card debt is holding you back. Paying off that tab should be a priority. Once you've done so, put the money you used to send to credit-card companies into your retirement savings plan.