40% of Americans say they can't afford retirement

NEW YORK (CNNMoney) -- Gone are the plans to golf, garden or read on a creaky porch swing.

Almost 40% of working Americans said they will never afford retirement, according to a report released Wednesday by the American Institute of Certified Public Accountants.

Retirement ranked as the most important issue out of all financial concerns facing Americans, including uninsured medical expenses and rising education costs. In fact, it topped the list for the second year in a row, the survey said.

The majority, or 56%, of those polled said they were not saving for retirement, mostly because of the toll higher gas and food prices were taking on their budgets.

Fifty-five percent said they didn't even know how much they need to save for retirement, while those that thought they did know often underestimated the amount, the AICPA said.

When asked to estimate how much savings they needed to retire at age 65 and live for 20 years, most of those earning $50,000 to $75,000 a year said they needed $250,000 in savings. But assuming inflation and annual expenses of $50,000, that amount would run out in less than 10 years, the AICPA said.

"These statistics suggest we are on the verge of a retirement crisis in America," Jordan Amin, chairman of the National CPA Financial Literacy Commission, said in a statement. "Americans don't know how to prepare for their twilight years, and many have put off figuring it out because they're struggling to make ends meet now."

Mark Carruthers, a New York-based certified financial planner who specializes in retirement planning, said many of his retired clients often take distributions from their IRAs or other accounts to supplement their retirement savings.

"I haven't met a client yet who just told me they saved too much for retirement," Carruthers said. "Most people don't start early enough and aren't investing long enough to reach their goal."

Younger workers had the biggest discrepancy between expectations for retirement and how to prepare for it, according to the AICPA. Sixty percent of those aged 18 to 24 said they'll be able to retire, but 74% of those in that age bracket had no idea how much to save to make that happen.