The average participation rate in 401(k) plans dropped 3.6 percentage points this year, to 72.6%, says a new survey of more than 3,200 plans by Plansponsor.com. It is the second year participation fell.

Last year, after nearly 20 years of increases, average participation fell 2.5 percentage points.

Much of the drop is in small and midsize plans. "That's a disquieting trend, because those workers don't usually have anything else to lean on," says Nevin Adams, editor of Plansponsor.com. Typically, only very large employers offer workers both a traditional pension and a 401(k) plan.

The 401(k) plan defections aren't the only worrisome sign:

• Only 39% of Americans think they'll have enough money to live comfortably in retirement, says a report by marketing consultants RoperASW. The only other time the level was that low was in 1995, when doubts about the solvency of Social Security peaked.

Only 30% of Americans count on income from savings and investments in retirement, the report says. That was the first time the figure dropped below 40% in 29 years.

• The number of Americans who save for retirement has reached record lows. Only 42% routinely set aside money for retirement, the lowest since 1980, according to Roper.

That is much lower than the 401(k) participation rate because it includes workers who have no company-sponsored retirement plan.

The biggest drop in retirement savings was among Americans ages 45 to 59, Roper says. Just 41% of the group are now saving for retirement, down 17 percentage points from 2001.

• Among workers who took a distribution from a 401(k) plan last year, 42% cashed out when they changed jobs, according to Hewitt Associates. The others rolled the money into an IRA or moved it to a 401(k) plan at a new employer.

Cashing out exposes workers to tax penalties and hurts their retirement future, says Stacy Schaus, at Hewitt Associates.

There are a number of reasons for the trends, experts say. Higher health insurance premiums are one.

"People say, 'I've only got so much discretionary income, and so retirement is something I'll put off until another day,' " Adams says.

In addition, many Americans are counting on rising home values to replace their retirement nest eggs, says Tom Miller, managing director of Roper.