Nearly a third of Americans have no emergency savings

Here's another piece of evidence that a substantial number of Americans live on the edge financially: Nearly 30 percent, or 66 million Americans, don't have a piggy bank to raid in the event of an emergency.

This finding by Bankrate.com comes five months after the site reported that about 63 percent of Americans wouldn't be able to handle a $500 car repair or a $1,000 emergency room bill.

The latest poll found Gen Xers to be in the worst position, with 33 percent of 36-51 year-olds saying they have zero in savings versus 27 percent of all others 18 or older. Bankrate conducted this survey of 1,000 adults in early June and released the findings on Tuesday.

Most financial advisers, including Bankrate chief financial analyst Greg McBride, recommend an emergency savings fund that can cover at least six months' worth of expenses. While only 28 percent of Americans have put away this much, that percentage represents a six-year high and is a marked improvement from last year's 22 percent.

The likelihood of having saved at least six months' expenses increases steadily after age 25, with the Silent Generation, or those 71 and older, leading the way at 47 percent.

"This underscores the fact that it takes time, especially because expenses grow faster than many Americans can save during the home-buying, family-raising years," McBride noted in a news release. "Accumulating emergency savings requires establishing the habit, and millennials get high marks."

Two-thirds of 18-35 year-olds have some savings, although just 20 percent have the suggested six months' expenses in the bank, Bankrate found.

While alarming in many regards, the survey marked the 25th consecutive month that Americans' financial security improved. Men reported better financial security for 28 consecutive months, and women said the same for 16 of those 28 months, including eight of the past 12.