It’s hard, and expensive, to find and retain good employees; conservative estimates place the average cost to recruit and train a new employee at half an employee’s salary.

With that in mind, it’s no surprise that companies are willing to try all sorts of things to make sure people stick around. One thing lots of companies have tried is establishing corporate mentorship programs, in which newer employees are paired up with veterans who can show them the way. Evidence suggests they bolster recruiting, boost employee engagement, help train future company leadership, increase diversity, and raise rates of worker loyalty and retention, and one study, by researchers at University of California-Santa Cruz, estimated that an investment in mentoring programs for new teachers returned $1.50 for every $1 spent, after taking into account how much less money was spent on credentialing teachers and how much better students performed.

It’s now more likely than not that America’s biggest companies have initiatives like these. According to the Association for Talent Development, a Virginia-based nonprofit focused on workplace learning and professional development, more than 70 percent of Fortune 500 companies have some type of mentorship program. About a quarter of smaller companies do.

So, do they work? Only if they’re done well. Crafting a successful mentoring program can be a much more difficult task than it seems, and unfortunately, such programs often flounder. They don’t have the buy-in they need from executives to succeed, and many people find them to be formulaic and pointless. That can ultimately be detrimental to employees and the company.

There are many problems with the existing model of corporate mentorship, says Jennifer Labin, the principal partner of TERP Associates, a firm that specializes in creating public- and private-sector mentoring programs. “Mentoring programs have become this band-aid,” Labin says. She adds that, in her experience, programs are often “thrown together by overworked, overwhelmed people who’ve never built mentoring programs.” Many people in these roles have often never even been mentored themselves, according to Labin.

Part of the problem is that many programs are based on old ideas of how jobs and careers work. In the book Intelligent Mentoring, by Audrey Murrell, Sheila Forte-Trammel, and Diana Bing, the authors assert that the more traditional approach to mentoring—in which an older (and often white and male) senior employee chooses a younger (and often white and male) protégé to take beneath his wing—is outdated. The main reason this is the case is that one-on-one mentoring was pioneered during a time when it was normal for people to stay in the same full-time job, at the same organization, for years—if not their entire career. Although there is research to suggest job-hopping is not as prevalent as believed, social expectations of corporate loyalty have waned. And few companies have adapted to this. While many have implemented mentoring programs, they haven’t tackled the more difficult task of figuring out what type of mentoring is necessary for their specific workforce.

When Lester Wright, the mentoring-program manager at NASA’s Goddard Space Flight Center, first arrived at Goddard, he found a program that he says was based on dated, rote mentorship models that weren’t as effective as they could be. Wright has worked at Goddard for about five years, but the mentoring program has been around, in some form, for over two decades. The mentoring program aged along with Goddard’s workforce, over half of whom are 50 years or older, without much change. It was up to Wright to work on assessing how effective NASA’s mentoring program is, and how it might be improved.

Wright set out to create a more structured approach to mentoring and expanded opportunities for mentors and mentees to connect by incorporating e-mentoring, so that relationships could thrive even when a mentoring pair weren’t in close proximity. It seems to be working. Recently, the Goddard Center earned high marks for its training and development programs. Out of over 300 federal agencies tracked by the nonpartisan Partnership for Public Service, Goddard’s training-and-development programming was ranked number 11 last year. “Our employees pretty much stay here forever,” Wright said.

According to Wright, much of the problem with corporate mentorship programs is that they miss an opportunity to create a formal, structured path for mentors and mentees. Outside of work, there are plenty of informal mentorship opportunities, but companies have the opportunity to facilitate more directly impactful relationships—and they often squander it. This becomes a more pressing issue as more and more workers age into retirement, since companies risk losing a wealth of data and information as millions of people exit the workforce without passing much of it on.

Whether an initiative works inside an organization is as much about competency as it is culture. “You could have the best design in the world, you could spend $75,000 and have all the bells and whistles, but it could fall flat on its face if people don’t have the [mentoring] skills to be successful,” Labin of TERP Associates says. Getting those skills can be tough in complex organizations with so many moving parts and competing priorities.

Labin says that for other sorts of corporate-training programs, a highly trained consultant might be hired for a set period of time to focus on implementing a new process. But that’s rarely the case with mentoring initiatives. When companies put people with very little training and even less time in charge of constructing these programs and provide them with unclear expectations, they set them up to fail.

Ironically, the factors underpinning the rise of corporate mentoring might also be contributing to its troubles. Much of the resurgence in formal, corporate mentorship programs can be traced back to a major McKinsey report, “The War for Talent,” which suggested that in a global market, the best talent is in short supply and that organizations must compete to attract and retain the brightest minds.

But it is those same forces that now undermine the quality of the programs. In a Harvard Business Review article, “Why Mentoring Matters in a Hypercompetitive World,” the authors, Thomas J. DeLong, John J. Gabarro, Robert J. Lees, suggest that the global market is putting so much strain on corporations that investment in mentoring programs is atrophying. “The starkest reality of surviving in the professional service industry is that competition is fierce,” they write, adding, “In the face of such pressure, something has had to give ... and it’s been the mentoring process.” As a result, the quality of mentoring programs has declined and the versions that emerged became, as the authors described, “a stylized charade devoid of any real learning.”

What makes this so dangerous for companies is that there is more harm to be done by bad mentorship than there is good to be done by great mentorship. Researchers have established that negative mentoring experiences caused more intense emotional and behavioral responses among employees compared to positive incidents. More, the ramifications of failed mentoring relationships can lead to emotional, psychological, and even physical ailments. And feelings about poorly executed mentoring programs can translate into negative feelings about a company. When a company has a lackluster mentoring program, Labin says, “you start to erode trust in the organization.”

The fact that companies are still struggling to address basic mentoring challenges can dampen the hope of addressing the more nuanced mentoring issues around, say, race, gender, or generational differences. But the improving labor market might provide an opportunity to reinvigorate existing mentoring programs. One theory is that when labor markets are tight—that is, when jobs are easier to come by—employers invest more in employee perks, which could be a boon for mentoring programs. For smaller firms especially, highlighting a commitment to quality training and development can provide an advantage in markets where big salaries from bigger firms often win out in the competition for talent.

But it’s hard to fix mentoring programs if employers don’t ask for feedback and employees don’t tell them what’s wrong. And that may be the case in many places. When I reached out to a group of elite, professional women about their experiences with workplace-based mentoring, hardly anyone volunteered to share stories on the record, for fear of professional blowback. One woman simply wrote, “Try to avoid formal programs at all costs. Torture.”

The key to creating better mentorship programs, Labin said, is to be more thoughtful in the planning stages. Last year she helped design a mentorship program for a startup. Concurrently, she worked on a mentor program with the U.S. Army Reserve Legal Command. “There’s no way a mentoring program that fits one is going to fit the other,” she told me. For example, a company with an aging workforce focused on knowledge transfer might benefit more from requiring mandatory program participation, while a company focused on encouraging employee engagement would benefit from making participation voluntary. It’s this type of individualized, company-specific approach that holds significant promise for the future of mentorship programs.