42% of Americans have less than $10,000 saved for retirement

CNBC -About 42 percent of Americans have less than $10,000 saved for when they retire, according to a study by GoBankingRates.

The No. 1 reason most people cited for not stashing more away was because they didn't earn enough to save, followed by the fact that they were already struggling to pay bills, GoBankingRates said. The personal finance site polled more than 1,000 adults online.

Although millennials are most likely to have less than $10,000 saved, older Americans are also becoming steadily more pessimistic about their future economic prospects, according to a separate study by United Income, a start-up that aims to apply big-data analysis to financial planning.