School principals need supervisors, too. But in Denver, most haven’t been in the role for long.

Eighteen of the 22 administrators who oversee Denver school principals have been on the job for three years or less, leading to concerns about a lack of stability and illustrating the difficulty of keeping the highly trained supervisors from being hired by other districts.

In the past few years, several of the supervisors — known as instructional superintendents — have left Denver Public Schools to take top positions elsewhere, including superintendent of the Oakland school district, assistant superintendent of the Philadelphia school district and deputy superintendent of the Dallas school district, according to a DPS spokeswoman.

Others have retired after long careers, while some have taken higher-level administrative jobs within DPS — moves that Superintendent Tom Boasberg called “healthy and natural.”

The district doesn’t track turnover among instructional superintendents the same way it tracks teachers and principal turnover because there are far fewer instructional superintendents (22) than teachers (nearly 6,000 last year, according to state statistics).

As a result, the district can’t provide an instructional superintendent turnover rate. But it did provide a breakdown of how long the current instructional superintendents have been on the job.

Five have been in the role less than a year. Another five have been on the job for one year. Four have been instructional superintendents for two years, and four have three years under their belts. The longest-serving instructional superintendent has been in the role six years.

The issue of instructional superintendent turnover came up at a recent school board work session that featured a panel of principals and supervisors answering questions from the board about their relationships and training. One elementary school principal said she’d been overseen by eight different instructional superintendents in 10 years. A high school principal said she was on her fourth instructional superintendent in four years.

“These are some of our most proven, successful and talented leaders, and we do worry about keeping them because they are getting recruited like crazy,” Boasberg said in an interview.

Most instructional superintendents are former school principals who were promoted to a supervisory role. Their jobs entail coaching and supporting a group of current principals.

Greta Martinez, a former instructional superintendent who is now one of the district’s two instructional superintendent supervisors, provided an example:

An instructional superintendent might sit in while a principal conducts a teacher observation, she said, and then compare notes with the principal to make sure he or she is properly evaluating the teacher’s instruction and skill level. The instructional superintendent might also help the principal brainstorm feedback to give that teacher.

But when turnover is high, it can impact the quality of the coaching instructional superintendents are able to provide principals. That’s because it can take anywhere from two to four years for instructional superintendents to “know their schools deeply,” Martinez said.

“Anytime you’re acquiring a new supervisor, it requires lots of new learning to happen,” Boasberg said. Conversely, “when someone understands the history of you as a leader and who you are and understands … your community, it makes the relationship much more effective.”

The principals on the panel echoed the superintendent.

“It’s difficult to learn the leadership style, the expectations year after year of a new boss,” said Kimberly Grayson, principal at Martin Luther King Jr. Early College in Montbello, who has had four supervisors in four years. “It brings on its own set of problems.”

Jill Corcoran, the principal of Westerly Creek Elementary, said the turnover can be frustrating.

“For every new (instructional superintendent), I’m supposed to adapt to them,” she told the school board members. “I just said, ‘I’m done. This is Westerly Creek. We need to figure out what’s working here and what’s not because we need to move forward.’

“Consistency is a really important piece: someone who not only knows me (but) knows my teachers, knows what’s working and then (can figure out) what do we need to change?”

In part to help mitigate the effects of turnover, several years ago the district came up with a new structure for its instructional superintendents. There are now “lead instructional superintendents” and “deputy instructional superintendents” who oversee every group of school principals.

All of the district’s current lead instructional superintendents are in at least their third year, Boasberg said. The lead instructional superintendents who oversee DPS elementary schools are even more senior. “That stability has been very welcome,” he said.

Other large metro school districts have similar supervisory positions, although they don’t call them instructional superintendents and they don’t have as many as DPS, the state’s biggest school district. Supervisors in other districts also tend to oversee more schools than DPS instructional superintendents, who are in charge of no more than eight each.

Jeffco Public Schools, the state’s second-largest district, has 14 “achievement directors” who oversee groups of 10 to 12 schools each. Terry Elliott, the district’s chief school effectiveness officer, wrote in an email that Jeffco plans for about two of the 14 to turn over every year “due to retirements, feeding other leadership positions — and yes, the occasional ‘steal’ by other smart districts that know we have high-quality leaders in Jeffco.”

Neighboring Aurora Public Schools has six “P-20 directors” who each oversee a group of schools. The district hasn’t seen any turnover since the positions were created toward the end of the 2013-14 school year, according to a district spokeswoman.

Meanwhile, the Cherry Creek school district has five “executive directors” who oversee schools, an assistant superintendent who supervises them and an associate superintendent who supervises the assistant. A district spokeswoman said they don’t see much turnover, either.

Overall, DPS officials said the role of instructional superintendent is an effective one that has benefitted both individual school principals and the district as a whole.

In recent years, DPS has invested heavily in training its instructional superintendents, even prodding the Relay Graduate School of Education — a national educator training organization — to design a program specifically for principal supervisors. Several instructional superintendents told the school board it was among the best training they’d ever done.

“The (instructional superintendents) play an absolutely critical role in supporting our principals and supporting our networks and we value them extraordinarily highly,” Boasberg said.

“We want to create positions where people are incentivized to remain,” he told the school board. But, he added, “we also recognize that our good (instructional superintendents) have a heck of a lot of good opportunities, and we need to be responsive to that.”