CHICAGO — Americans are changing the game plan for retirement, with millions laboring right past the traditional retirement age and into their late 60s and beyond.

While the average retirement age remains 63, that standard may soon be going the way of the gold watch — a trend expected to accelerate as baby boomers close in on retirement without sufficient savings.

For 64-year-old John Lee, "retirement" bears a strong resemblance to his full-time working career — full of 40- and 50-hour weeks as an IT technical support specialist. He's not strapped but likes the extra cash and the feeling of being needed.

But for Melissa Fodor, a retired travel agent who works part time as a caregiver for the elderly, the extra work "keeps my head above water" and there's no end in sight to that financial need at age 68.

Growing evidence documents that people are working longer as they live longer.

Twenty-nine percent of people in their late 60s were working in 2006, up from 18 percent in 1985, according to the Bureau of Labor Statistics. Nearly 6 million workers last year were 65 or over.

Over the next decade, the number of 55-and-up workers is expected to rise at more than five times the rate of the overall work force, the BLS reported.

A slowing economy and stock market, squeezing funds set aside for retirement, also are contributing.

In an April survey conducted for AARP, 27 percent of workers age 45 and over, and 32 percent of those 55-64 said they had pushed back their planned retirement date because of the economic downturn. The telephone poll by Woelfel Research interviewed 1,002 respondents and carried a sampling error margin of plus or minus 3.1 percentage points.

"We have people who are healthier, who are living longer and have more economic reasons to stay in the work force," said David Certner, AARP's legislative policy director. "On the employer side, you have greater demand for experienced (older) workers. That all adds up to longer work lives."

Lee never envisioned putting in long work weeks in his mid-60s.

The Marietta, Ga., resident battled frequent work stress before taking early retirement from Coca-Cola Co. at 55.

But when his old employer called offering contract work at his specialty, mainframe systems, he gladly accepted. Tennis and golf hadn't worked out as retirement hobbies, and he decided he could use the money for occasional trips overseas and to help out his children and grandchildren.

"Going back to work wasn't the plan," he said. "But after I retired, before they called me, I really didn't have anything to do. So when they called, I jumped on it."

Lee, who makes more than $50,000 from the contract work, isn't the only one in his house working after retirement. His wife Joyce, 60, also took early retirement but went right back to work as a real estate agent.

They say the extra household income supplements their combined $3,000 a month in company pension payments and adds to $1.3 million in assets to assure their retirement will be financially comfortable — if and when it happens.

Working longer is generally the best option for those who come up short on retirement savings. And with many people's investment portfolios and 401(k)s down significantly in recent months, it has become a compelling alternative for many retirees or near-retirees to having to live on less.

"It's always been a good idea, but right now it can be an especially good idea," said Christine Fahlund, a senior financial planner with T. Rowe Price. "You really don't want to be pulling more money out of a portfolio that's already down."

In a recent report, the investment management group said continuing to work full time past one's anticipated retirement date could increase annual retirement income by about 7 percent for each additional year of work.

Working another three years — from 62 to 65, for example — and continuing to save 15 percent of salary could raise annual income from investments by 22 percent. Make it five years and boost savings contributions still higher — even better.

Putting off retirement also may enable people to delay when they start taking Social Security benefits, which can significantly increase payments.

"The longer the delay, the better" financially, said Fahlund. "To me the ideal would be 70, because you get the biggest Social Security benefit possible and all those additional years of employment. And it keeps you going mentally and physically too."

If toiling extra years doesn't sound very palatable, a wanna-be retiree may wish to consider spending some of the additional work earnings on hobbies, travel, education or other retirement dreams to make it seem more worthwhile.

"Delaying retirement does not necessarily mean delaying gratification," Fahlund said.

Such a strategy, she said, could still increase retirement income from investments by 4 percent per year, or 12 percent after three years, since the retiree would not have to tap existing savings.