Memorial Day may have ushered in summer, but fewer Americans are blowing the bank on a vacation — a symptom, experts say, of the persistent challenges American households have getting their balance sheets into the black.

According to Experian's 2018 State of Credit report, average credit card balances rose from $6,354 in 2017 to $6,506. This is an improvement over 2008, when the average was $7,101, and the percentages of delinquencies have either remained steady or fallen, with the biggest year-over-year drop in the most severely delinquent borrowers.

A recent Bankrate survey found that 60 percent of Americans who aren’t taking a summer vacation this year said it’s because they can’t afford it. Although 22 percent of those said the money was going to pay down debt instead, twice that number said just keeping up with day-to-day bills was preventing them from having money to take a vacation.

“Americans have made progress on debt — paying it down, refinancing debts at lower rates,” said Bankrate chief financial analyst Greg McBride. “In terms of the amount of monthly income going to debt payments, it’s among the lowest it’s been in 35 years, and we do see reluctance to add to that debt for discretionary spending.”

The amount of monthly income going to debt payments is among the lowest in 35 years.

McBride added that much of this is driven by debt-averse millennials who came of age during the last recession. “Chalk that up to lessons gleaned from having a front row seat in the financial crisis,” he said.

But these signs of progress could be undone by our lack of savings. The Federal Reserve’s Report on the Economic Well-Being of U.S. Households in 2018, released earlier this month, found that many households are living with a razor-thin margin of error: Roughly 40 percent wouldn’t be able to cover an unexpected expense of $400 with cash, savings or a credit card they could pay off in full right away.

“Even in an economy where we’re essentially at full employment, expenses and discretionary spending are chewing up the paychecks,” McBride said.

Whether or not people could shoulder an unexpected $400 expense easily was closely correlated to their debt load: Nearly 90 percent of people who never carry a credit card balance said they could pay this expense with cash or its equivalent, while only 40 percent of those who regularly carry a balance said the same.

“Americans are woefully under-saved for emergencies. We routinely find that about a quarter of households don’t have any emergency savings, and the majority of Americans are still well short of the destination of six months’ worth of expenses in emergency savings,” McBride said.

The Fed survey found an increase in overall optimism. Three-quarters of Americans characterized their overall financial status as okay or living comfortably, an increase of 12 percentage points since 2013.

“People are feeling good about a lot of different aspects of their financial lives, but not savings,” McBride said. “That’s a big turnaround from where we were a dozen years ago, [when] people were letting their appreciating homes and 401(k) balances do the savings for them."

People today want to save, he said. “It’s just been difficult to move the needle.”

Of greater concern to experts are the 17 percent of respondents to the Fed survey who said they couldn’t pay all of their current month’s bills in full.

“It highlights the skewing of income and wealth. Even in the best of times, we have a large segment of the population that’s unable to save,” said Mark Zandi, chief economist at Moody’s Analytics. “A large number of Americans are living on the financial edge. They have a job, wage growth is improving but their balance sheet is still very fragile. They have no financial cushion.”

The Fed report also underscored the bifurcation of financial stability in the U.S. “Another year of economic expansion and the low national unemployment rates did little to narrow the persistent economic disparities by race, education, and geography,” it said.

Since the record-long bull market will come to an end at some point, this segment of the population is essentially living on borrowed time, Zandi cautioned. “It’s very important that the economy continues to perform well to allow more people to get their financial house in order — save more, pay down debt, build up the cushion everyone will need at some point,” he said.