Research among more than 1,000 over-60s found that working longer was becoming the norm.
Only about one third of those at state retirement age were not working at all, with many others working part-time or taking on consultancy or voluntary work.
Insurance firm LV= said it was clear from its study that many people were now taking a more gradual approach to retirement, slowly cutting back on their working hours rather than stopping altogether.
More than one in four of those working later in life were running their own business, while one third had switched careers. One in six of those questioned said they had returned to work after retiring.
Richard Rowney, managing director of life and pensions at LV=, said: "For many people, working for longer is a positive choice. Many people in their sixties and seventies enjoy their jobs and are keen to remain active in later life."
Meanwhile, figures from the Pensions Regulator reveal that four million people have now been placed into a workplace pension scheme as the Government's retirement savings revolution rolls out.
To date, 21,000 employers have completed a "declaration of compliance" that shows they have met their auto enrolment duties. Hairdressers, colleges and scrapyards are among the latest wave of employers to have been brought into to the scheme.
Pensions Minister Steve Webb hailed the scheme as a "tremendous success".
So far, a much higher than expected rate of about nine in 10 people are staying in their pension scheme rather than opting out after they have been automatically enrolled.