The Obama administration on Thursday reminded public schools across the country that they are not allowed to block children from enrolling just because they are not legal residents of the United States.

Attorney General Eric Holder and Education Secretary Arne Duncan released new guidance to public schools meant to ensure schools adhere to a 1982 Supreme Court decision that says schools must allow everyone to enroll, even if they or their parents aren’t U.S. citizens.

Eric Holder Arne Duncan immigration education

United States Attorney General Eric Holder reminded public schools on Thursday that they cannot exclude children from enrolling based on their immigration status. (AP Photo/Seth Wenig)

“Recently, we have become aware of student enrollment practices that may chill or discourage the participation, or lead to the exclusion, of students based on their or their parents’ or guardians’ actual or perceived citizenship or immigration status,” the reminder said, which was released in both English and Spanish.

Holder said that since 2011, the Department of Justice has worked on guidance to help schools understand their responsibilities under the law. But he said some schools are flouting this requirement — including by requiring certain documents for enrollment that only U.S. citizens would have.

“Public school districts have an obligation to enroll students regardless of immigration status and without discrimination on the basis of race, color, or national origin,” he warned. “The Justice Department will do everything it can to make sure schools meet this obligation.”

The new guidance says schools should be flexible in accepting documents from parents that prove a child’s age and show that the child lives in the school district. For example, it says schools can request phone and water bills as proof of residency in the district.

But the guidance says schools cannot deny enrollment because a student has no birth certificate, or has only a non-U.S. birth certificate.

“While a district may restrict attendance to district residents, inquiring into students’ citizenship or immigration status, or that of their parents or guardians would not be relevant to establishing residency within the district,” it says.

The guidance also says schools cannot deny enrollment to children who don’t provide a Social Security number. It says if schools choose to ask for a Social Security number, it must tell the family that supplying that number is voluntary.

“If a district chooses to request a social security number, it shall inform the individual that the disclosure is voluntary, provide the statutory or other basis upon which it is seeking the number, and explain what uses will be made of it,” it reads.

“We want to be sure every school leader understands the legal requirements under the Constitution and federal laws, and it is our hope that this update will address some of the misperceptions out there,” Duncan said. “The message here is clear: let all children who live in your district enroll in your public schools.”