In a tight market, it’s only natural for hiring managers to throw out a massive net, posting across all kinds of platforms in their search for that elusive perfect candidate. But this method can sometimes overlook another great way to find skilled teammates: considering the potential talent you already have, right under your nose.

Research shows that hiring from within a company can encourage more longevity, because your hire is familiar with the team and may feel more trusting of leadership. A survey from SmartRecruiters found that a promoted employee has a 75% chance of staying at a company for the next three years. And they may stay longer if you make a role more interesting and diversified.

With today’s competitive job market, “it is important to consider all sources of untapped talent,” says Jon Cermak, a talent manager at Salo, a firm focusing on finance and HR talent. Here are four types of internal candidates you should definitely consider:

1. INTERNS

Sure, current (or former) interns may not have all of the training that more senior candidates have, but they are already familiar with how your culture works and how they can fit into it.

Moreover, many young employees are eager to learn and develop the level of acumen bosses and hiring managers are looking for. Online platforms have reported a recent boom in younger employees seeking out opportunities to level up their skill sets—and a quick training after hiring can often help make up for any experience they might be lacking.

The enthusiasm this cohort has as they embark on the very beginning of their careers means they will likely be ready to dive head-first into new projects and develop the skills required in today’s evolving workplace.

2. RETIRED EMPLOYEES

This group of employees may think they’re done with their careers, but sometimes time away from the office (and a consistent paycheck) can make this subset of workers reconsider.

When you open up opportunities to these older set of workers, you may find they are eager to come back and offer their expertise. It also might be worth considering bringing someone on in a flexible, part-time capacity, says Jon Cermak. Think creatively. Perhaps they would like to help on a specific project or serve as a mentor to help develop new talent.

3. BOOMERANG EMPLOYEES

Boomerang employees are workers who left looking for greener pastures, but were disappointed by what they found—or realized their old job was actually a pretty good fit after all.

It’s possible some of these ex-employees have just not yet made their way back to your company. They may still be seeing what opportunities out there. If you have a former hire who was great at their job, it’s worth reaching out and seeing if they’d have an interest in returning—perhaps in a slightly different capacity.

4. CONTRACTORS WITH SOME SORT OF EXPERIENCE IN YOUR COMPANY

In a tight hiring market, recruiters should think about people with unique expertise and a familiarity with your company’s line of work. A great source of untapped talent that fits this bill are contractors, many of whom work remotely. Often these workers have delivered value before and know how your firm operates, so they may be a great fit especially on a condensed hiring time frame—for permanent positions, or for to fill an immediate need.

“Think about [your] short-term and long-term hiring strategies,” says Cernak. “Sometimes, you’re in a pinch and really need someone to fill a role. This is where consultants, part-time or full-time, can come and fill in an urgent need, so you can work thoughtfully to fill a role for the long term.”