One of the few things you can control about Social Security is when to start collecting it. Should you take it when you become eligible at age 62, wait until normal retirement (a function of your birthdate) or consider delaying your benefits past normal retirement age?

To help you make this decision, consider that, on average, Americans are living longer than ever before. Clearly, the longer you expect to live, the more sense it makes to delay taking Social Security. But of course, each person’s circumstances and needs are different — here’s a look at how timing can affect the beneifts you recieve.

Early benefits

The earliest you can collect Social Security is age 62. But taking payments at 62 will result in a permanently reduced benefit, ranging from a 20 percent reduction for people born in 1937 up to 30 percent for those born in 1960 or later. You may want to consider early benefits if you need income but prefer to leave your portfolio intact, or if you intend to invest the benefit to try to earn a more competitive return — though there is no guarantee you will do so.

Full benefits

Eligibility for full Social Security benefits varies according to the year you were born. Depending on how long you worked and how much you earned over your lifetime, the maximum benefit you could collect at normal retirement age — 65 years and 10 months — is $2,185 per month in 2008. Consider waiting for full benefits if you plan to work until age 65, if you want to ensure a larger survivor’s benefit for your spouse or if your family history and good health may lead to an above-average life expectancy. Refer to the Social Security Web site, www.socialsecurity.gov/OACT/quickcalc/when2retire.html, to calculate your “breakeven” age, when the accumulated value of higher benefits from postponing retirement will start to exceed the value of lower benefit from choosing early retirement.

Delayed benefits

If you continue working beyond your naormal retirement age, you will be eligible to collect a permanently increased Social Security benefit when you do retire. Approximately 8 percent more per year will be added automatically to the permanent benefit amount for every year you wait. Delaying benefits past age 70 will generally add nothing more to your monthly benefit.

To help assess your situation, refer to your personalized Social Security Statement, which estimates the monthly Social Security benefits you may qualify for — go to www.socialsecurity.gov/mystatement for a copy of your statement. You may also wish to enlist the help of a financial professioanl to crunch some numbers and determine what sort of timing would best support the retirement you envision.

Bill byrne is a financial planner at Smith Barney in Natchez.