You can't start collecting Social Security retirement payments until you turn 62. But financial planner Andrea Zoeller says it's a good idea to start thinking about your benefits by your 50s.

How Long You Work and How Much You Make Matter

The Social Security Administration (SSA) calculates your benefit by determining your monthly average income over the 35 highest-earning years of your working life, adjusted to account for historical changes in wages.

Holding on to a well-paying job for its own sake may not be the right choice for everyone nearing retirement age, says Zoeller. But it's important to consider how a late career shift or a move to part-time work could affect not just your present income but your future Social Security payment.

Benefits Get Bigger the Longer You Put Off Taking Them

You can claim retirement benefits as early as age 62, but you only become entitled to your full benefit — 100 percent of the amount calculated from your lifetime earnings — when you reach full retirement age (FRA), which is 67 for people born in 1960 or later.

If you claim before then, Social Security reduces your benefit by a fraction of 1 percent for each month remaining until you reach your FRA. Those fractions add up: If you file when you turn 62, your benefit will be 30 percent lower, and that reduction is locked in for life.

The flip side is that there's a bonus for waiting past your full retirement age. For each month beyond FRA that you put off filing, Social Security adds to your eventual benefit amount. By waiting until 70, the age when your benefit maxes out, you'll get 24 percent more than you would by filing at full retirement age — and 77 percent more than if you had filed at 62.

Deciding when to file may not just be about getting the biggest benefit. Your health or finances might argue for an early start. What's important is understanding the ramifications so you can make an informed decision when you reach claiming age.

You Can Get a Preview of Your Benefit

Your Social Security statement, accessible online if you have a My Social Security account, shows your estimated retirement benefit for each claiming year from 62 to 70, based on your past and projected future earnings. You can get similar estimates by plugging your age and income information into AARP's Social Security Calculator.

These estimates are inexact; they don't reflect possible swings in your income before you retire, for example, or the positive impact of future cost-of-living adjustments (COLAs). Your eventual benefit may be different. But they do provide a baseline for what you can expect from Social Security.

You Can Help Ensure Your Benefit Is Accurate

It's worth taking the time to verify the SSA's record of your annual earnings, says Zoeller. She and other financial advisers say their clients have spotted inaccuracies, such as missing years of income or incorrect wage amounts, and those can affect your eventual payment.

The SSA says the most common causes of errors are employers reporting incorrect wage amounts on W-2s filed with the agency or providing the wrong employee name or Social Security number. Failing to report a name change to the agency (for example, if you get married or divorced) can also result in earnings being unattributed or misattributed.

You'll Need Other Sources of Income

Social Security was never intended to fully replace retirees' work earnings. On average, retirement benefits cover about 40 percent of your past income (the proportion is typically larger for low-income workers and smaller for high earners).

The rule of thumb from financial advisers is that you need to replace around 80 percent of your working income to maintain your lifestyle in retirement. Factoring in expected Social Security income can help you strategize to bridge the gap.

For example, you might step up contributions to an IRA or 401(k) so you'll have more savings to draw on, or decide you want to work a little longer. These additional income sources can also help you put off filing for Social Security, thus increasing your lifetime benefit.

Your Retirement Benefit Might Not Be Your Biggest Benefit

If you are married, or were, you could be eligible down the road for benefits on both your own earnings record and that of your mate. That holds true even if the marriage ends due to divorce or death.

Social Security calls this "dual entitlement." It doesn't mean you'll get two benefits combined; the SSA will pay you the higher of the two amounts. That means you could get a spouse, divorced-spouse or survivor benefit rather than your own retirement payment, if your mate is, or was, the higher earner in the house.

Be sure to check your potential eligibility for these family benefits and investigate related claiming strategies as part of your Social Security planning. They could provide paths to higher lifetime benefits and greater financial flexibility in retirement.

Social Security Isn't Going Away — But You Might Get Less From It

Social Security's finances do need attention. A $2.7 trillion cash reserve in the trust funds from which benefits are paid is projected to run out in 2034, according to the latest annual report from the program's trustees. But that's just the surplus. Social Security would continue to collect the payroll taxes that workers pay into the system each year; that incoming revenue would cover about 80 percent of the promised payments.