KEY TAKEAWAYS

• Critics of interdistrict open enrollment (IOE) argue that allowing students to cross district boundaries will disrupt district enrollments and, in turn, disrupt district finances.
• However, we find no evidence that IOE increases enrollment volatility, and if there are no major enrollment disruptions, there can be no funding disruptions, because funding changes due to IOE follow from enrollment changes. Thus, our findings give no evidence to suggest IOE will disrupt district budgets.
• We further find no evidence that the introduction of IOE leads to mass migrations of students into popular districts, or out of unpopular ones. This is partly explained by the fact that even in states with strong IOE policies, the overwhelming majority of families continue to enroll their children in their resident districts. Commonsense features of IOE policies also help — for instance, one reason that popular districts are not overrun is that they are not required to admit students beyond their capacity.
• Alternatively, proponents of IOE argue it can transform public education by sparking meaningful interdistrict competition for students. Our findings do not entirely rule this out, though they suggest it is unlikely, at least in the first five years.
• Holistically, our results suggest that IOE is not a systemic disruptor of the residentially based school assignment system. Instead, it appears to provide increased mobility for a relatively small but meaningful share of families for whom the local district is not a good fit. While IOE is unlikely to produce the sweeping changes anticipated by its strongest advocates or feared by its strongest critics, it can still help many families have better educational experiences.

Interdistrict open enrollment (IOE) allows public K–12 students to enroll in schools outside of their residentially zoned districts. Many states have IOE policies; Missouri does not. Policies in some states allow students to move between districts with few restrictions, while in others they are quite restrictive.

Proponents of IOE point to several benefits of the policy. First, it expands families’ options to find schools that meet their children’s needs. IOE advocates claim it can help students zoned to persistently low-performing schools to access better educational opportunities. It can also help with other challenges, such as families attempting to distance themselves from bullies, or families of students with Individualized Education Plans (IEPs) that the local district is ill-suited to implement. Regardless of why a family wants to move, IOE provides new options.

A related concern is school safety. Recent guidance from the federal Department of Education signals a renewed commitment to the Unsafe School Choice Option (USCO) in federal law. USCO dates back to the 1965 Elementary and Secondary Education Act and requires states to ensure that students in persistently dangerous schools are provided the opportunity to attend a safe public elementary or secondary school. IOE is one channel through which the requirements of the law can be satisfied.

Zooming out, proponents also argue that IOE could produce systemic effects by encouraging competition between districts. The logic is that with sufficiently expansive open enrollment, local school districts can no longer count on geographically “trapped” families to enroll. Competition brings out the best in service providers in other sectors of the economy. Why should education be different?

Opponents generally do not dispute that individual families should have choices. Rather, they focus on concerns about equitable access, the erosion of local governance, and the potential for IOE to disrupt school district enrollments. The latter concern is arguably the most prominent in policy debates about IOE in Missouri. The worry is that with IOE in place, student mobility

could cause large enrollment fluctuations across districts. These fluctuations would make district management more difficult, causing some districts to be overwhelmed with students while leaving others underenrolled. Some struggling schools, or even districts, could close. Schwalbach (2023) provides a recent overview of these concerns.1

Lurking beneath the surface is the issue of school funding. Large enrollment fluctuations can change enrollment-based funding from the state. Districts that lose too many students could face financial pressure. A related concern is that districts with substantial local funding — presumably net importers of students in a well-functioning IOE environment — would be obligated to spend their local resources on students from outside the district, whose families are not contributing local taxes.

However, these potential effects depend fundamentally on how IOE influences student enrollment patterns. Despite heated rhetoric, there is little empirical evidence on IOE’s effect on district enrollments. We fill this gap in research by conducting an empirical evaluation of how statewide IOE policies influence district enrollment patterns across five states: Colorado, Kentucky, Oklahoma, Tennessee, and Wisconsin. These states reflect the full spectrum of IOE policy strength across the United States, from restrictive to expansive. In each state, we construct a data panel tracking school and district enrollments for five years before and (when possible) five years after IOE implementation.

At the outset, there is good reason to expect that the disruptive effect of IOE will be limited because even in states with strong and mature policies, most students continue to enroll in their residentially assigned districts. For instance, IOE participation rates in states with long-standing, highly rated IOE policies such as Arizona, Colorado, and Wisconsin range from 8 to 12 percent of K–12 students, while in other states — even some with strong policies — rates often fall between 1 and 5 percent (e.g., Arkansas, Oklahoma, and West Virginia).2

Given these participation rates, the argument that IOE is a system disruptor seems limited. This is especially true if districts are commonly both senders and receivers of students. However, the potential for IOE to disrupt enrollments could be larger if the enrollment shifts it facilitates are sufficiently concentrated. For instance, if students disproportionately use IOE to move into or out of particular districts, these districts could see large changes even if most districts are unaffected. This ambiguity underscores the need for our empirical analysis.

Our findings give no indication that IOE policies lead to meaningful changes in district enrollment stability within the first five years. We generally cannot distinguish district enrollment fluctuations after the introduction of IOE from business-as-usual enrollment fluctuations that occurred prior to its implementation. This finding is robust to several different measures of enrollment fluctuations, including measures meant to isolate acute enrollment increases in high-demand districts and enrollment decreases in low-demand districts. In addition, there is no evidence that IOE leads to school or district closures.

These findings suggest that many of the points raised on both sides of the IOE debate are largely moot. For instance, opponents imagine extreme inequity emerging from IOE whereby some districts are left with populations of acutely needy students because all others have left (National Education Policy Center, 2022). Ignoring the obvious moral issue of the implied alternative — that is, is it desirable to trap some students in areas of concentrated need to support their highest-need peers? — there is no evidence of such mass migrations occurring via IOE. Similarly, opponents’ concerns about the erosion of local school governance (and local funding support) do not hold up, because districts do not experience substantial influxes of out-of-district students due to IOE.

On the proponents’ side, our analysis provides no support for the claim that strong IOE policies will transform public education by sparking meaningful interdistrict competition for students. We cannot rule out systemic competitive effects conclusively because the limited enrollment response to IOE could be inclusive of such effects. For instance, enrollment shifts in response to IOE may fail to materialize if weaker districts quickly improve in response to the competitive environment. Still, although we cannot rule out this explanation entirely,

we view it as less likely than simpler alternatives. Our preferred explanation is that even when IOE policies are strong, most families choose not to participate. The fact that most students choose to attend a local district school, even with IOE in place, is consistent with a 2024 survey from EdChoice showing that the top reason families give for choosing a public school is proximity.3 There are many explanations for this — for example, most families are happy with their local school, transportation is convenient, and they prefer to send their children to the same school as their neighborhood friends — but the bottom line is that relatively few families cross district boundaries, limiting the potential for IOE to generate systemic change.

Where does this leave us? Our findings are consistent with IOE facilitating district mobility for a meaningful number of families, but not enough to disrupt the larger school system. This takes the wind out of the sails on both sides of the debate to some extent, but it is important to acknowledge that the opportunities afforded to these families via IOE can be quite valuable to them. IOE is unlikely to have the transformative effect on public education that the strongest proponents of the policy might hope for, or that the strongest opponents might fear, but it can still help many families have better educational experiences. The Reason Foundation’s 2025 report “Public School Without Borders” identifies 16 states that have strong statewide IOE policies.6 Missouri technically has an open-enrollment policy on the books, but it scored very poorly in the report — tied for second to last among all states — because the Missouri policy is severely restrictive and is for all practical purposes currently defunct. The one exception in Missouri is that during the 2025 legislative session, a law was passed allowing school employees, along with contractors who work for a school, to send their children to that school even if they are not district residents. This is the extent of IOE in Missouri today.