NEW YORK (MainStreet) — Half of all working Americans want a retirement-savings do-over as they fall short of their goals.

TIAA-CREF's Ready to Retire survey reveals that and a lot more that once again points to a retirement savings landscape where millions of Americans believe they won't have enough cash to live on in retirement and wish they’d emphasized "financial readiness" capacity during their saving years.

The report says 52% of Americans approaching retirement say "they wish they had started saving for the future sooner" and that many worry about not having enough money to cover their monthly expenses (45%), while others are anxious about how health care costs (35%) or inflation (32%) could deplete their retirement savings.

As usual with surveys on Americans and their retirement savings, there's a disconnect in what savers say they need to accomplish and what they actually accomplish. For example, 45% of survey respondents age 55-64 say "financial readiness is the most important factor in determining when they will retire," but only 35% say they saved in an IRA or met with a financial advisor.

Regret about what could have been also dominate the survey. "Many respondents say they wish they had made smarter financial decisions earlier in their career, including saving more of their paycheck (47%) and investing their savings more aggressively (34%)," the report says. As a result, TIIA-CREF reports that 68% of Americans near retirement say they are "not prepared" financially and another 42% say they will have to keep working in retirement and 39% must "limit" what they spend.

"This research reinforces that preparing for retirement shouldn't become a sprint to the finish, but rather a long-distance pursuit that requires careful planning throughout an adult's life," says Teresa Hassara, an executive vice president at TIAA-CREF.

The survey results should act as a prod to better saving habits. "This will help prevent those nearing retirement from feeling like they have to play catch-up near the end of their careers," Hassara says. "Developing and acting on a carefully constructed plan can help individuals at any age build a financially secure future."

The news isn't all negative for slow savers. Hassara says many older workers can make up a lot of ground if they act right away. "If Americans find that their retirement savings aren't adequate to meet their expectations about retirement life, it's never too late to make adjustments," she says. "In fact, if a 55-year-old starts to max out his or her employer-sponsored retirement plan contribution next year and continues to do so for the next 10 years, those savings could grow to about $325,000."

— By Brian O'Connell for MainStreet