Applicants over the age of 50 beating the streets in today's IT job market bear resumes that are commonly stigmatized as pricey and outdated, given recent leaps in technology and sweeping operational changes at many companies. Yet this crowd may prove to be the IT profession's salvation, especially over the next four years as baby boomers retire from the workforce in droves.

While some industry experts and executives claim that the looming baby boomer exodus is a lot of hype, most argue that its impact can't be overstated. The numbers seem to back up the latter position. In 2010, about one out of every three workers in the U.S. will be over 50. In 2012, there could be as many as 21 million vacant jobs but just 17 million workers to fill those posts, according to The US Computing Technology Industry Association.

IT employers are just waking up to the mounting crisis of baby boomers walking out the door en masse. These mature workers will take with them valuable institutional knowledge and the skills needed to run legacy systems. Savvy corporations should think right now about maintaining ties with older workers who are looking to power down -- but not entirely abandon -- their careers. Another corporate must-have: solid mentoring programs that pair up-and-coming IT executives with seasoned professionals.

"I don't believe the concern for a baby boomer talent exodus is overhyped at all," says Steven Naylor, vice president and director of IT at FHL Bank Topeka. "Clearly, there will be a significant shortage of talent as a result of an aging, retiring IT workforce. I personally believe there is only a moderate level of awareness regarding this issue among most companies."

FHLBank is part of an industry expected to be hit especially hard when baby boomers leave. Other markets that need to move quickly toward stopgap measures are the insurance, telecommunications and retail industries, as well as the automotive and aerospace sectors of the manufacturing industry, according to several industry watchers.

Government is also vulnerable. "About 400,000 federal employees could retire tomorrow," says Robert Rosen, CIO at theNational Institute of Arthritis and Musculo skeletal and Skin Diseases, which is part of the National Institutes of Health. Rosen is also president of Share, a Chicago-based IBM user group. "Obviously, this is a concern at NIH."

Concern over the loss of experienced IT talent also pervades FHLBank, which is therefore moving fast to address issues coming down the pike. "We are taking active steps to partner [more mature] individuals with less experienced staff on projects," says Naylor. "We are encouraging younger workers to volunteer and assume responsibilities for support activities normally held by more seasoned individuals, and we are exposing younger workers to direct training opportunities."

Rent-A-Center (RAC), an electronics and furniture rent-to-own business has a similar strategy. "We are focused on growing our own leaders, and the biggest reason for this is the value we put on corporate knowledge and the emphasis we put on retaining that knowledge. It promotes our culture and helps define a career path for people," says David Oles, IT director of research and development at RAC.

Still, RAC and other organizations are not so quick to write off older workers. "Mature workers who experienced their prime working years in a different time don't want to be overlooked for training and development," says Oles.

Indeed, many baby boomers are not ready to be put out to pasture quite yet -- nor can they afford to be, according to Sandy Berger, host of US-based AARP's computer and technology Web site. "Don't overlook the fact that many baby boomers who are retiring from one profession are going on to create new careers for themselves," she says. "They will stay within the same IT field but will choose jobs that they prefer or that actually better suit their strengths."

For many workers nearing retirement, life-balance issues are crucial. Thus, they may consider a move to contractor status. "In the height of the knowledge management boom, we created an employee-emeritus program," says Dan Rasmus, director of information work vision in Microsoft's information worker group. "This way, when we have an employee retire, we can rehire that employee at a pay scale worked out ahead of time or put in place a scenario where that employee works one day a week."

Not all aging workers, however, are set on becoming contractors. Many need benefits and are open to moving into lesser positions in order to keep them. In such cases, an organization may transfer IT leadership to younger workers but retain older workers in non-management roles. That way, they don't lose institutional knowledge, and they keep employees happy. "Older workers may not want the top jobs. The may be looking for less responsibility, less stress," says Neill Hopkins, CompTIA's vice president of skills development.

If seasoned workers aren't retained, employers could suffer across the board. Mature workers now hold down many project management positions that can make or break major IT initiatives. "Cross-functional skills necessary for project management center on the ability to make sure everybody is on the same page to keep a project aligned," says Gary Cormier, executive vice president at BrassRing, a talent management company.

To get younger workers in position to take over project management and other broad IT responsibilities and to preserve corporate knowledge, industries will ultimately have to band together, says James Kelley, performance management project leader at Idaho Power. "Long term, the solution is to collaborate as an industry with educational and legislative institutions," he says. "The engineering class of 2015 is in middle school today. We need to be out there recruiting the seeds that will bear fruit in the next decade."