he big Social Security Myth: It ensures that we're financially "secure" in our later years. Fact: Its own financial future is in peril. In other words, don't count on Social Security as a guaranteed source of income 20 years from now.

It's hard to imagine surviving retirement without the comfort of monthly Social Security checks arriving in the mail. Before 1935, Americans did exactly that, however. It took the abject poverty of the elderly during the Great Depression to convince Congress to approve President Roosevelt's plan for basic subsistence payments to senior citizens.

The program's salad days started in 1972, when benefits were linked to the nation's inflation rate, guaranteeing recipients that their monthly payments would rise with each year's cost of living. The party's over. The burden on working Americans grows each year. Payroll taxes siphon 6.2 percent of the first $68,400 a person earns - an all-time high. Congress and the White House continually squabble over how they will keep the program solvent into the next millennium.

From a financial planning perspective, Social Security is a double-edged sword. The program has a positive impact because it provides a basic level of retirement income. The flip side is that Social Security engenders a false sense of security, lulling many people into thinking they do not need to work very hard and sacrifice very much to save for retirement because those government checks will just keep rolling in.

Times have changed since 1935, and for the worse. When Social Security was started, there were 16 workers paying into the system for every retiree receiving benefits. Now, only three workers contribute per retiree and by the year 2020 the ratio will be two to one - two workers paying in for every retiree taking out. Unless massive changes are made in the Social Security system, deficits are projected to begin in 2012 and the Social Security program will run out of money altogether in 2029.

What does this mean for your retirement planning? You should count on getting something, but "something" is not going to increase with inflation. Your retirement benefits depend on the number of fiscal quarters (or three-month increments) you have worked, the amount of your annual income in each of the last 35 years of your working life and your age at retirement.

The higher your earned income, the more your monthly benefits will be, although these increases are not proportional. For example, let's assume that you are single and your lifetime income inched upward from year to year. If you received $30,000 during your last year of work, your monthly benefits would start at $1,059. But if you double your income to $60,000, the benefits only increase 15 percent, to $1,217.

Benefits provide a minimum level of coverage, but don't expect to live on Social Security alone. The average monthly payment in 1996 was $720. Women are particularly vulnerable to lower benefits - they often leave the work force for periods of time to raise children, and they generally received lower pay than men throughout their working lives.

Regardless of your exact future benefits, Social Security is still an important part of your retirement planning. The best way to start is by finding out your estimated benefits through the Social Security's Personal Employment Benefit Estimate Web site.

This report shows your estimated annual benefits at age 62, at your "normal" retirement age (65 to 67, depending on your year of birth), and at age 70. These are estimates of future benefits, with an actual dollar amount at that time. If a projected benefit is $1,500 a month at age 65, that may sound terrific to you now because you're thinking of what $1,500 buys today.

There are some important steps to take when you get your report. First, check your reported earnings for each year you worked. Just like any other bureaucracy, mistakes are made.

Second, take a good look at how your benefit varies according to your retirement age. If you retire at 62, generally you will only get 80 percent of your benefits at normal retirement age. Conversely, you will get an extra 8 percent for each year you work past your normal retirement age. If you're married, your non-working spouse will get 37.5 percent of your benefits if you retire early, and 50 percent at your normal retirement age.

Remember that the normal retirement age is no longer always 65, and that it will begin to rise starting with workers retiring in 2000. Looking at your various retirement benefits, you can figure out the best time for you to start taking Social Security.

Third, decide how much you want to rely on Social Security. The younger you are, the more likely it is that your benefits will be less than projected. As a safety measure, you might assume your actual annual benefit would be 75 percent of current estimates. Whatever your method, plug that Social Security number into your retirement needs analysis to see how much you will have to save on your own to provide the income you want. Then make a plan to save even more than that, if you can.

One final tip: When you deal with the Social Security Administration, do it in writing. If doing so is impossible, go to a Social Security office. Use the telephone as a last resort. Whether in person or by phone, take copious notes, and get the employee's name and ID number of the employee with whom you are dealing.

You won't be penalized if you receive incorrect information from the employee and you have proof. If you are not happy with the Social Security Administration's decision about your situation, you can file a "reconsideration." You can also ask to have any deadlines waived until your problems are resolved.

Social Security was never designed to pay for a life of luxury, but even with its current fiscal woes, you can probably count on something when you retire. There are several "rescue" plans on the table now, allowing workers to invest some of their Social Security contributions themselves, allowing the federal government to invest some of the programs' billions in the stock market, and making other massive changes to the system. Whatever the outcome, it's clear that the days of guaranteed, steadily increasing benefits are over.