The population may be aging, but that hasn’t gotten a lot of Americans to plan for retirement. About 71% of Americans lack a formal investment plan to help them reach their retirement goals, according to one study.

The study, conducted by the ING Retirement Research Institute, showed that nearly half (48%) of respondents aged 25 to 69 who are employed full-time and earn at least $40,000 a year don’t feel prepared for retirement. That’s despite the fact that 75% of that same group do contribute to their workplace’s retirement plan.

“The good news is that more people are becoming aware of what it takes to reach their goals,” said Maliz Beams, CEO of ING U.S. Retirement.

But there’s still work to be done in this area, clearly. The study also found that only 43% of those surveyed calculated how much money they will need to continue their current lifestyle once they retire. And only 28% are working with a financial professional to help meet objectives.

There were 4,050 adults, roughly evenly split between men and women, surveyed for the study during one week in October 2011, ING U.S. said in a statement.

Danielle Reed writes for Financial Planning.