Many US workers are delaying retirement despite an improving economy, according to a recent survey released by CareerBuilder.

The survey found 53% of workers aged 60-plus said they are postponing retirement, with 57% of men putting retirement on hold compared to 48% of women. Four in 10 workers, 40%, don’t think they will be able to retire until 70 or older.

“Postponing retirement will make an impact across all of our country’s workforce, along with retirement policy and financial and health care planning,” said Rosemary Haefner, chief human resources officer at CareerBuilder. “With workers staying in their jobs longer, employers are adjusting hiring needs, but also reaping the benefits of the extra skills and mentoring abilities of mature employees.”

Approximately a quarter of survey participants, 24%, do not know how much they will need to save for retirement. Women are much more likely to be unsure of how much to save than men at 31% to 17% percent, respectively.

When asked if they're currently contributing to retirement accounts, 23% of workers age 55-plus said they do not participate in a 401(k), IRA or other retirement plan.

The survey was conducted online within the US by The Harris Poll on behalf of CareerBuilder. It included 809 employees and was conducted between Nov. 28 and Dec. 20, 2017.