At age 81, Thomas Cooper has had a bout with cancer, and endured a back operation, but neither has convinced him to retire.
Instead, five days a week you'll find him selling men's shoes at a Nordstrom store in Bethesda, Md., just outside Washington D.C.
"I would go crazy sitting around the house," Cooper told ABCNews, "So I work."
A new study indicates he is hardly alone, according to government data analyzed by the AARP Public Policy Institute.
"The number and the proportion of people, 75 and older, in the work force, they are on the increase," said Sara Rix, a Senior Strategic Policy Advisor with the Institute. "What we're seeing is really quite a remarkable increase in attachment to the labor force over the past 20 years or so."
According to the AARP analysis, in 1990, just 4 percent of the 75-plus crowd worked, now that's up to 7 percent. That equates to nearly 1.3 million people in this age group who are employed. It's a small percentage of the overall workforce, just less than 1 percent, but that's still more than double the percentage a few decades ago.
Perhaps even more astonishing is that their unemployment rate has jumped as well, meaning a lot of these folks are looking for work. AARP's analysis found the unemployment rate for the 75 and older group was 2.3 percent in 1990. It was 5.6 percent last year.
Rix said there's a host of reasons behind the increases. For one, individuals can continue to work because they're staying healthier longer.
"I suspect most people are there because they're doing something they really want to do. They enjoy their work. They're making a contribution."
There are also financial considerations. With the drop in home prices, the fluctuating stock market, and the decline in pensions, some older workers simply have to work.
For Cooper, that's definitely part of the equation.
"When you get my age, you have a lot of doctor bills and different ailments. You have to pay the doctors and hospitals, so I am here," he said.
A recent survey by Wells Fargo found that nearly a third of Americans figure they'll need to work until age 80, in order to retire comfortably. The federal government estimates that by 2020, 10 percent of those aged 75 and older will be in the labor force. Rix believes the number is likely to be even higher.
Just last week the issue of older workers hit a chord on Capitol Hill, when House Minority Leader Nancy Pelosi was asked whether she should give up her leadership position to make way for younger lawmakers. Pelosi, who is 72, later told ABC News's Martha Raddatz that she was "amused" by the question, although at the time she called it "quite offensive."
Pelosi questioned whether male lawmakers would be asked the same age question.
Rix agreed: "So it may have been not only age discrimination implicit in that question, but perhaps also sex discrimination, as well. If someone can do that job, that's what we ought to be focusing on."
Shoe salesman Cooper believes older workers offer an advantage.
"They have more experience, they know the products better, they know how to talk to people, and that's what matters."
Cooper, who's been in the shoe business for decades, but got his current job 17 years ago at the ripe young age of 64, says he has no plans to retire.
"I've been very fortunate that most of the managers here have been very good to me," he said. He was worried that "you get to a certain age and they want you out of here," but that hasn't happened to him. So his plans are to stay on the job. "I am going to keep working until I can't do it anymore."