Technical Appendix
This appendix is a companion to the report. It provides details on research design, data sources, and information to back key findings.
Understanding the Increase in Assistant Principals
Roles, District Structures, and Diversity
Why assistant principal ranks grew in three large districts, how district structures shape the path to the principalship, and who advances.
October 2026
Table of Contents
Document
- Author(s)
- Mariesa Herrmann, Ellen Goldring, Angela Cox, George Smith, and Mollie Rubin
- Publisher(s)
- Mathematica Policy Research, Vanderbilt University, and Policy Studies Associates, Inc.
Page Count
39 pages
Summary
How we did this
The authors collected more than a decade of records from three large school districts to observe educators’ movement across job roles and career progressions, as well as their race and gender. From late 2023 through 2025, they interviewed current central office leaders, principals, and assistant principals for the study. The focus was the staffing of assistant principals, design of their roles, hiring and placement, professional learning and mentoring, as well as advancement to the principalship.
Assistant principals have become increasingly central to how schools operate and support students. Many public schools now employ two or more of these education leaders.
But evidence is limited on what drives staffing decisions and how principals allocate responsibilities across assistant principals.
This study examines assistant principal staffing, roles, and hiring in three large districts—two urban, one suburban. It also documents the assignments, support, and advancement opportunities available to assistant principals in those school systems.
The share of schools with multiple assistant principals increased in all three districts over the decade studied, from 2011-12 to 2021-22. But these leaders were deployed in different ways. In one district, assistant principals were assigned to schools that previously had none. In the other two, new assistant principals were added to schools that already had them.
Leaders in the three districts linked the growing ranks of assistant principals to increased student needs and complexity of school operations. They cited the need for stronger instructional leadership and for greater safety and supervision.
The study also provides a snapshot of how assistant principals spend their time. Most, according to school leaders interviewed, focused on instructional leadership (such as classroom observations and coaching teachers), followed by providing various types of support to students and families.
Across all districts, assistant principals of color were more likely to work in schools with students who shared their racial or ethnic backgrounds. In some schools, the race and gender of assistant principals shaped their daily assignments and access to experiences that might help advance their career. Some assistant principals of color reported an additional, less-visible workload, particularly related to discipline and parent engagement, because they were perceived as more relatable to students and families. At the same time, in all three districts, Black men were more likely than white men to become principals within five years of entering the assistant principalship.
But people of color remain underrepresented among both principals and assistant principals, even as research suggests students of color can benefit from leaders who share their racial or cultural backgrounds.
This is the third in a Wallace-supported series of reports by the authors that examine assistant principals. Together, the research delivers complementary insights about:
- The scope of assistant principal staffing nationally
- District-level conditions that impact the support assistant principals receive
- Equitable access to developmental opportunities
- Pathways to a more diverse school leader workforce
Because the assistant principalship is a key entry point to the principalship, it is also central to efforts to diversify school leadership.
Key Takeaways
- In all three districts studied, assistant principal staffing grew in aggregate from 14% in 2012 to 51% in 2022, outpacing student enrollment. District leaders cited rising needs for instructional leadership, safety, and student support.
- Assistant principals spent the most time on instructional leadership. In some schools, principals rotated duties to prepare assistant principals for future principalships.
- Centralized leadership programs helped give assistant principals a clearer path to becoming principals. When schools managed hiring and mentoring, moving up depended more on each principal.
- Some assistant principals of color described being steered toward discipline and parent and community engagement, which could affect their access to other leadership experiences needed for the principalship.
- The authors suggest districts and policymakers consider funding assistant principal roles based on school needs beyond enrollment, while monitoring how placement and assignments affect access to the principalship.
Materials and Downloads
What We Don't Know
Many important research questions remain unaddressed. Among them:
- Will assistant principal positions keep growing as student enrollment declines in many districts, and what would cuts mean for leadership stability and equity?
- How do different assistant principal staffing models affect principals’ time, staff retention, school climate, and teacher and student outcomes?
- Do assistant principals’ day-to-day responsibilities—such as discipline versus instructional leadership—predict later advancement, retention, and effectiveness as principals, and does that differ by race and gender?
- How do hiring and placement decisions interact with school context to shape long-term advancement for educators of color and women?
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