As we head into the second decade of the 21st century, the concept of retirement has taken on a whole new meaning for many Americans.

“The traditional idea of a full-time retirement at age 65 is being rethought by some,” says David Lerner, CEO of David Lerner Associates, an investment firm in Long Island, N.Y. “They prefer to view their retirement years as a time to ‘rewire’ instead of retire.”

There are several reasons for this shift in thinking. The average life expectancy of Americans continues to rise. I’s now 78.7 years for men and women in the United States, according to the Centers for Disease Control and Prevention, and it’s not unusual for Americans to spend 20 to 30 years or longer in retirement.

Advances in medical technology have led to longer and healthier lives as well. Many people who have reached the traditional retirement age aren’t ready to sit in a rocking chair on the front porch for the rest of their lives – they prefer to remain vibrant and active instead. They want to find meaningful activities that will keep their bodies healthy and their minds sharp.

Don’t retire – rewire

In other words, they need to “rewire,” not retire. For individuals like this, the possibilities are limited only by the imagination. Among the most common rewiring activities that are being undertaken by many so-called retirees today are:

* Working part-time. The ideal scenario for many people is to ease into retirement by staying at their existing jobs on a part-time basis or finding another part-time job in an activity they love.

* Starting a new business. Many people spend their lives thinking of ideas for new businesses that never get off the ground because they don’t have the time or resources required to actually launch the business. Retirement could be the perfect time to make your entrepreneurial dreams a reality.

* Advancing education. The fact is you’re never too old to learn something new. You could go back to school during your retirement years simply to learn more about a subject that has always fascinated you or to obtain the training and education needed to start a brand new career.

* Traveling and spending time with family. After perhaps an entire lifetime of creating a “wish list” of places you’d like to visit, you may finally have the time to visit them after you retire.

* Pursuing hobbies, sports and other recreational activities. Spending your retirement years on the golf course is something of a cliche, but if that’s what you enjoy, then your retirement years may give you plenty of time to indulge. The same goes for any other hobby, recreation or sport you’ve always loved but never had much time to participate in.

* Volunteering to support favorite causes. Whether it’s pitching in at your place of worship, helping feed the homeless at a local shelter, or spending time raising funds to combat a disease that you feel passionately about, volunteering can become like a second career during retirement.

Funding your “rewirement”

Of course, few (if any) of these activities will be possible without a sound retirement financial plan. If you haven’t done so yet, now is the time to sit down with your financial adviser and begin planning investment and distribution strategies that will fund your “rewirement.”