NEW YORK (MainStreet) — How long can retirees count on Social Security? The system is currently funded to pay full benefits only until 2033, according to the Social Security Administration. How to address the shortfall will no doubt be an issue Washington debates for years. In the meantime, many retirees who have earned Social Security benefits feel they may have left a great deal of money on the table as a result of a decision they now regret: taking benefits too soon.

More than one third (38%) of retirees wish they had waited longer to begin receiving Social Security income. Faced with rising health care costs, nearly three-quarters of Americans say they rely on Social Security for out-of-pocket health care costs, according to a Nationwide Financial Retirement Institute consumer survey.

Those health care costs can quickly deplete Social Security benefits. For a healthy, middle-income couple retiring next year at full retirement age, medical expenses are estimated to absorb 69% of their Social Security benefits. But ten years from now, those costs will jump to 98% -- and in 20 years, the same couple would require 127% of their Social Security benefits to cover health care costs in retirement.

The survey of 903 adults aged 50 or older, who are either already retired or plan to retire in the next ten years, revealed those who began receiving Social Security income early report a lower average monthly payment ($1,190) than those who started at their full retirement age ($1,506) and those who delayed benefits until age 70 ($1,924).

"Social Security can represent up to 40% of the total income the average worker receives throughout retirement and when and how to file are some of the most important financial decisions they make in their lifetimes," said David Giertz, president of distribution and sales for Nationwide Financial. "With more than 2,700 rules in the Social Security handbook, it's easy to see why many aren't aware of all of the benefits and options available to them."

Getting good advice regarding Social Security benefits can help – if pre-retirees can find a financial consultant adept at interpreting the multitude of regulations. Only 12% of those surveyed had an advisor that offered advice on Social Security. One-third of retirees without a financial advisor say health care costs keep them from living the retirement they expected – compared to just 13% of retirees with a financial advisor.

--Written by Hal M. Bundrick for MainStreet