Are you ready for a financial emergency?

An often-heard rule of thumb for financial health is to keep an emergency savings fund to cover unexpected events like a job loss. But if you're like most Americans, you've fallen behind in tucking money away for that rainy day.

By some measures, the economy is showing improvement, with unemployment falling and the stock market hitting new highs this year. But a stubborn problem for Americans is stagnant wage growth, which makes it increasingly difficult to put away money, especially as prices for everything from food to clothing keeps climbing.

No wonder 26 percent of U.S. consumers lack any emergency savings, according to a new Bankrate survey. On top of that, two-thirds of Americans have saved less than the recommended six months' worth of expenses, the survey found.

"We've surveyed this for several years in a row since the recession, and these numbers have not improved," Bankrate chief financial analyst Greg McBride told CBS MoneyWatch. "What make that notable is that the lack of progress comes at a time when consumers realize more than ever the importance of emergency savings."

While the recession ended five years ago this month, many Americans are still living paycheck-to-paycheck, making it difficult to put money aside in an emergency savings fund. About 25 million middle-class Americans live "hand-to-mouth," a recent study out of the Brookings Institution found.

Even the middle class is finding it difficult to put money away for an emergency, Bankrate found. For Americans with average household income of $75,000 or more, only 46 percent have a six-month savings cushion, the report notes.

But it's not entirely the fault of American consumers and their spendthrift ways. The real pressure is coming from the intersection of higher prices and stagnant wages, which is affecting all but the top earners, McBride noted. From 2000 to 2013, hourly wages for most Americans either fell or flatlined, according to a study published earlier this month from the liberal-leaning Economic Policy Institute.

Some generations are better prepared than others to face a life emergency, though. The age group most likely to have money set aside are Americans between 18 to 30 years old. The worst off? Those between 30 to 49 years old.

People between 18 to 30 "had a front-row seat for the recession and the ensuing anemic recovery," McBride said. "They recognize the importance" of having money tucked away.

Those between 30 to 49 "have the house, the two cars, the three kids and the dog," he added. "They need emergency savings more than anybody." Their lack of savings "is a reflection of how many people are living paycheck-to-paycheck."

At the same time, Americans are feeling more confident about their jobs and their debt levels, Bankrate found.

"The 401(k) balance is going up, so you have a higher net worth," he said. "You're not fearing the Friday afternoon pink slip, so you feel better about job security. You've managed to pay off bills, but the paycheck hasn't increased," which is leading to low savings rates.