It seems like the days when people would stay with a single employer for decades are long gone.

The numbers say that millennials—the most populous generation in the U.S. labor force—change their jobs at three times the rate of older generations. A resume packed with frequent job hops no longer carries the stigma it once did.

Changing attitudes about employment are combining with a booming economy to generate the highest quit-rate in years. And more than half of American workers are looking for a new job or watching openings.

In other words, if an employee isn’t highly engaged, they’re out the door.

For HR professionals and managers, the situation can be aggravating. Turnover can cost an organization as much as twice an employee’s salary. It’s not just about the cost of finding and training a replacement; it’s the cost of losing valuable experience and institutional knowledge, and the effect turnover has on morale.

Making matters even more challenging, you can’t always be sure why employees leave. Departing employees tend to be less-than-candid in their exit interviews—if they sit for an interview at all. It’s becoming more and more common for employees to simply “ghost” their employers like they would a bad date.

With so much working against you—a labor-friendly job market, a culture that encourages career restlessness—how can you keep your best team members from jumping ship?

Here are five of the most common reasons employees leave, according to experts and polls. For each reason, we’ve suggested a possible remedy to help you increase employee retention.

1. Unsatisfactory Pay

Salary is not the only reason people look for work elsewhere, but it remains the number-one motivating factor among job seekers. In today’s job market, leaving for more money isn’t the risk it once was.

Solution: Make sure your employees are paid at least the market rate for their work—if you’re not certain, sites like glassdoor.com, salary.com, and payscale.com can provide useful benchmarking. Explain your pay structure clearly, so there are no surprises.

Also, recognize that employees may think about their compensation in terms that go beyond dollars and cents. Flexible work schedules, good benefits, and employee wellness programs can be just as enticing to employees as pay bumps.

2. Lack of Recognition

Sometimes, people just want to know all their hard work is being noticed. Nearly 80% of people who quit their jobs say lack of recognition played a role in their decision. And 22% of employees who say they don’t feel recognized for their great work have interviewed for a job in the last three months.

Solution: When employees receive regular praise, they not only tend to stay in their jobs, but they do better work. Make it a point to acknowledge your employees regularly for all they do for your company. Don’t limit your praise to specific accomplishments; employees want to feel valued for who they are, not just what they do.

(Recognition can be a powerful motivator for participation in your wellness program, as well.)

3. Poor Cultural Fit

In a survey of 25,000 employees around the world, employee engagement company TinyPulse found that workers who rate their workplace culture poorly are 24% more likely to quit. Employees want to work with people who share their values and give their work a sense of purpose.

Solution: Define your corporate culture and communicate it clearly across your organization. More importantly, strive to reflect your stated mission and values in all that you do. For example, if your company says it’s committed to sustainability (as 90% of millennials are), make a real attempt to reduce waste, recycle, and conserve energy.

4. Work-Life Imbalance

Today’s workers are eschewing the workaholic mentality that their parents embraced. They want time and flexibility to handle family responsibilities, pursue their outside interests, and live healthy lifestyles. According to one recent survey, 30% of respondents said they left a job because it did not offer flexible work options.

Ironically, modern technology is making it harder for employees to leave the office at the office. Email, text messages, and chat alerts demand attention at all times of day, on weekends, and sometimes, even on vacation.

Solution: Aim beyond work-life balance (an overused buzzword, anyway) and toward a culture of work-life integration. Work-life integration acknowledges that work and life don’t have to oppose each other, the office isn’t the only place where work can happen, and rigid schedules often drive up stress levels and drive down productivity.

5. Lack of Growth Opportunities

Doing the same thing day-in and day-out can get tedious after a few years—especially if you think you’re capable of so much more. People want to work for companies that will invest in their careers.

A Harris Poll survey found that a third of employees who quit their jobs did so because they weren’t gaining new skills. More than three-quarters of employees feel “on their own” when it comes to career development.

Solution: Check in with your employees regularly about their professional goals and ask what your company can do to help. Make continuing education and career development part of your employee wellness program.

Employee retention comes down to listening. Human nature will always pull toward the greener grass on the other side of the fence. But if you pay attention to what your employees want and make a genuine effort to deliver—before they think of leaving—you’ll keep more valuable workers on your team.