WASHINGTON — Out-of-school suspensions dropped 20 percent nationally in recent years, but students of color and students with disabilities are still more likely to face harsh discipline than their peers, according to new federal data.

The Department of Education said Tuesday the drop in suspensions from the 2011-12 to 2013-14 school years shows more schools are finding alternative ways to address nonviolent student behavior.

But sharp disparities endure in the results of the 2013-2014 Civil Rights Data Collection, which covers 50 million students in nearly every public school and school district in the country.

The data showed black students were more likely to be suspended than their white peers, a trend that begins in preschool and lasts through high school. They also were more likely to be expelled and referred to law enforcement.

In addition, students with disabilities were more likely to be suspended than their peers and disproportionately restrained or placed in seclusion.

“The CRDC data are more than numbers and charts — they illustrate in powerful and troubling ways disparities in opportunities and experiences that different groups of students have in our schools,” said Education Secretary John B. King in a news release.

Judith Browne Dianis, executive director of the civil rights organization Advancement Project, said the data illustrate “persistent racism” in schools.

“Schools must change policies that allow for subjective decisions on the basis of race and move toward police-free learning spaces,” she said.

School discipline policies are an area of concern for juvenile justice advocates. When students face suspensions and expulsions, they are more likely to drop out of school and end up in the juvenile justice system, a phenomenon known as “school pushout” or the “school to prison pipeline.”

The survey’s findings include:

• black children in preschool are 3.6 times more likely to be suspended than their white peers;
• black students in kindergarten through 12th grade are almost four times more likely to be suspended than their white peers;
• black students are 2.3 times more likely to be referred to law enforcement or have a school-related arrest as their white peers;
• students with disabilities are more than twice as likely to have one or more suspensions than their peers without disabilities; and
• students with disabilities in kindergarten through 12th grade who are served by Individuals with Disabilities Education Act  (11 percent) are more than twice as likely to receive one or more out-of-school suspensions as students without disabilities.

The Education Department highlighted its topline findings in a “first look” report with additional releases expected throughout the summer. In August, the survey data will be available in a data reporting tool.