Twenty New York school districts found to be blocking access for undocumented immigrant children will be forced to modify their enrollment policies to break down illegal barriers to education, the state attorney general’s office said on Wednesday.

A joint review by the State Education Department and the attorney general’s office found a broad pattern of intransigence on the part of districts that, despite repeated instructions from federal and state law enforcement agencies, continued to bar children based on their immigration status, said Kristen Clarke, the chief of the Civil Rights Bureau in the attorney general’s office.

The resulting reforms, under agreements between Attorney General Eric T. Schneiderman and the 20 districts, would compel them to stop asking for documents such as Social Security cards that effectively exclude undocumented children from school.

The state compliance review followed an article in The New York Times in October, which found that several suburban districts had contravened federal guidance by requiring immigrant families to provide proof of district residency before their children were enrolled. Families were stymied by school bureaucracies, and children, who are required by law to attend school, could not.