Even if minimum age for collecting Social Security remains the same, the majority of American adults will have to push their retirement back by a decade or more—continuing to work into their late 70s or early 80s—to make sure they can cover their expenses once they stop working, says a new study from the Employee Benefit Research Institute (EBRI).

Only about 52 percent of people will be "ready" to retire at the traditional 65 year-old mark, according to EBRI researchers.

For older adults who can put off retirement for a few more years, the outlook improves—a little. Sixty-four percent of those who are able to work until they're 70 will have enough money to cover their expenses in retirement.

These statistics run counter to another recent analysis, conducted by the Center for Retirement Research, which claimed that 86 percent of people could retire comfortably if they put off leaving the workforce until their late 60s.

Why were the findings of these two studies so different?

Three words: long-term care.

The EBRI analysis factors in the cost of long-term care for chronic illness, while the Center for Retirement Research analysis did not.

According to the Department of Health and Human Services, nearly 70 percent of people who live past 65 will need some kind of long-term care (in-home care services, skilled nursing, etc.).

Government programs only cover part of the cost of this care, leaving seniors with substantial bills that can soar well into the thousands.

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The EBRI researchers believe their model to be more realistic, but they caution adults nearing retirement to honestly evaluate their financial situations, instead of relying on "rules of thumb," when determining when to leave the workforce.

Adult children often wonder whether they should quit their jobs to take care of their aging parents.

Every individual's situation is different. It may not be possible for you to continue working and look after your loved one at the same time.

However, this new analysis underlines the importance of taking stock of your personal circumstances and the potential financial consequences of interrupting or terminating your career prematurely. Especially since these actions could impact your ability to pay for your own care.