Less than half of states are meeting their obligations to appropriately serve students with disabilities under the nation’s special education law, federal education officials say.

In an annual review, the U.S. Department of Education found that only 22 states deserved the “meets requirements” designation for the 2015-2016 school year. All other states were placed into the “needs assistance” category.

The findings issued this summer come from a mandatory assessment of state compliance with the Individuals with Disabilities Education Act. The ratings are based on how well states meet their obligations to serve students with disabilities ages 3 to 21.