More Americans expect to work past their 65th birthdays and never retire, says a recent study.

The Associated Press with the NORC Center for Public Affairs Research polled 1,075 people, age 50 and older.

One-fourth of them said they never plan to retire. Among low-income earners in that age group that is even more true than for high earners.

In America, the age of 65 is the traditional age to retire.

Sixty percent of people aged 50 to 64 said they expect to work past their 65th birthday.

More than half of those who are already older than 65 said they plan to keep working, too. They say they are working an average of 31 hours per week.

Those 50 years of age or older said finances are the most important factor in the decision to when to retire.

A majority of older workers — especially those who are 65 and older — plan to switch employers, or move into an entirely new profession, as they head into the later years.

One-third of people earning less than $50,000 a year said they will keep working. About 20 percent of those who earn more than $100,000 said they will never retire.

As baby boomers — people born between 1946 and 1964 -- reach age 65, the United States' general population will have more older people than ever before.

The number of Americans 65 and older jumped 21 percent -- or to 35.5 million -- between 2002 and 2012.

That number is expected to reach 92 million by 2060.

I'm Marsha James.

Dora Mekouar wrote this story for VOANews. Jim Dresbach adapted her report for Learning English. Kathleen Struck was the editor.