Departing the workforce entirely and entering retirement at age 65 is no longer a reality for many older people in the United States, according to a recent survey by The Associated Press-NORC Center for Public Affairs Research. The study finds that there are large numbers of older Americans who are currently, or who expect to be, working longer. However, this doesn’t necessarily mean that they are continuing with the same employment circumstances indefinitely. Many are either reducing their hours to part-time status or are planning to switch to a new employer or even a new field.

This survey comes at a time when the size of the older population is larger than ever and projected to keep growing. Between 2003 and 2013, the number of Americans age 65 and older rose from 35.9 million to 44.7 million. In the next quarter century, this number is expected to rise to 82.3 million. The percentage of the overall population that falls within this group will rise from 14.1 percent in 2013 to 21.7 percent in 2040.

“The circumstances and future plans of older Americans must be well understood by decision-makers,” said Trevor Tompson, director of The AP-NORC Center. “Not only are older Americans going to work longer, but 4 in 10 respondents are planning to change career fields in the future. These results point to significant changes in the American workforce with impacts likely felt by workers and employers.”

Key findings from the survey from adults age 50 and older:

A quarter of older workers say they plan to never retire. This sentiment is more common among lower-income workers than higher-income workers, with 33 percent of those earning less than $50,000 a year saying they will never retire, compared with 20 percent of those who earn $100,000 or more.

More than half of older Americans plan to work past the traditional retirement age of 65 or already have worked past age 65. Six in 10 Americans age 50 to 64 plan to work past the age of 65. Nearly half of those who are 65 and older say they already work or plan to work during this later stage of life.

The members of the workforce who are age 65 and older are not limiting themselves to occasional work–this group reports an average of 31 hours per week in the workplace.

More than 4 in 10 Americans age 50 and older have spent at least 20 years working for the same employer at some point in their careers. These workers are more excited and less anxious about retirement than those without such long histories with a single employer.

A majority of older Americans who are planning to remain in or rejoin the workforce are planning to switch either professional fields or employers in the future. Those who are age 65 and older are especially likely to plan a change.

A sizeable minority of older workers are taking steps to keep their skill sets fresh by pursuing job training or additional education.

A quarter of adults age 50 and older have looked for a job in the past five years. Many of them are encountering difficulties in the job market, with a third reporting that it has been so difficult that they’ve given up looking at some point during their search.

The 2016 study on working longer is a continuation of and expansion on a 2013 survey from The AP-NORC Center. The 2016 study extends the 2013 research and examines new topics, including older workers’ efforts to improve their career skills and their plans to adjust the parameters of work in the later stages of their working life. The survey also tracks a number of attitudes and behaviors that were examined in 2013 surrounding issues facing older workers.