New data collected by the U.S. Department of Education's office for civil rights provides an idea of how many students in the nation's public schools have so-called 504 plans. (Every few years, the agency gathers a huge collection of information from school districts about everything from which courses students are taking to how students who bully classmates are disciplined. Read about some of that here. Another conclusion: Students with disabilities are more than twice as likely to receive one or more out-of-school suspensions.)

It's been difficult to determine how many students have these plans, which don't provide students with special education services—the kinds of services that help them access the curriculum the way that individualized education programs, or IEPs, work under the federal Individuals with Disabilities Education Act. Instead, these 504 plans address accommodations that would help the students be on level footing with their unimpaired peers.

Some experts have estimated the number in the past. But in the Civil Rights Data Collectionfrom the 2009-10 school year, about 7,000 school districts were asked to report the number of students who have one of these plans. (A similar question was asked the previous time the data was collected, but the new numbers encompass more school districts and a larger proportion of public school students.)

This data set shows that 433,980 students across the country have 504 plans. It doesn't break down what they are needed for. And, in and of itself, the number doesn't mean a whole lot. Butnew guidance from the OCR could expand the number of students who use these plans.

However that new guidance didn't outline exactly what services this group of students, growing in number, is entitled to. And students with 504 plans don't have the kind of due process rights as students with disabilities who have IEPs.