As Susan Wilner Golden put it in her recent book, Stage (Not Age), it’s time to shift the American mindset away from defining people by their age and instead consider their stage, and what they have the skills and ambition to accomplish. 

Recent years have brought increased awareness and attempts to dismantle the systems of racism, sexism, and anti-LGBTQ discrimination in the workplace. The same awareness does not exist for ageism, which is often cited as the last acceptable “ism.”

Ageism became more visible in the political sphere as we approached the midterm elections. However, this form of discrimination remains prevalent in almost every aspect of American life.

With a tight labor market, businesses need new ways to attract and retain qualified candidates. Workers over 50 present an untapped opportunity: they are abundant, experienced, and other employers overlook them to their own detriment.

Older workers belong to the fastest-growing segment of the American labor force, according to the Bureau of Labor Statistics. This is due to the demographic trick of Baby Boomers aging along with increased longevity resulting in many older adults needing–or wanting–to work up to and past the typical retirement age. And why shouldn’t they? Or perhaps the better question is, can society afford to lose them?

Research shows the vast majority of both employers and fellow workers have a positive view of older workers. Studies on worker productivity find no difference between older and younger workers. In some cases, the contributions of older workers may even be greater. Counter to the oft-cited origin stories of Apple, Microsoft, and Facebook–all of which were founded when Steve Jobs, Bill Gates, and Mark Zuckerberg were under the age of 22–startup success is more likely for companies founded by middle-aged entrepreneurs. The average age of a Fortune 500 CEO is 57 and some are over 70, including Warren Buffett, who is 91.

Yet it remains true that employers view older workers as more expensive to employ (due to higher healthcare costs and wages) and more likely to be stuck in old ways of working. For these reasons, they are overlooked as promising candidates. During tough economic times in particular, they are often the first to be laid off and the last to be rehired.

Organizations under financial pressure may also offer older employees incentives to leave as part of a shortsighted strategy to reduce payroll expenses (it drains the organization of institutional knowledge). Companies commonly force retirement at age 60 or 65–when some people are at the high point of their careers–to make room for younger executives to move up. These practices and others contributed to the out-sized negative employment impacts older workers have faced during COVID-19.

Yet the economy cannot afford to push out such a large and experienced group exactly when we need as much talent as we can get. Consider the situation of the healthcare industry, which has warned of a looming physician gap for more than a decade. Around 40% of physicians working today will be 65 years old within the next decade. The pandemic sped up their retirement plans as already-high levels of burnout in the profession skyrocketed, leading more than 40% of physicians to consider early retirement.

Some version of the talent gap exists in every sector of the economy. Three in four HR professionals say their organization is struggling to fill critical roles. Most respondents cite a lack of candidates with the right experience and technical skills. 

Though “technical skills” is often code for “young”–that isn’t always the case. In the first year of the pandemic, banks and government agencies issued a desperate call for tech professionals able to code in COBOL–a 40-year-old programming language used on mainframe systems. The average age of a COBOL programmer? Around 55.

Contrary to the stereotype that older adults lack digital skills, the vast majority of the demographic is comfortable using the internet and active on social media platforms. Targeted advertisements and online listings are a great way to spread the word about opportunities, and flexible working arrangements like working from home and part-time hours can encourage more experienced workers to apply.

No organization can afford to let talented, experienced people walk out. Employers should take advantage of every talent source they have by tapping into the millions-strong pool of American workers over the age of 50. It’s not just a matter of developing a recruitment strategy for older workers: The workplace must also be primed to accept and get the most out of them. Available evidence suggests that here, too, society has a lot of work to do.

Alan Patricof is the author of No Red Lights: Reflections on Life, 50 Years in Venture Capital, and Never Driving Alone.

The opinions expressed in Fortune.com commentary pieces are solely the views of their authors and do not necessarily reflect the opinions and beliefs of Fortune.

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