City schools will now be required to conduct lockdown drills each year, in the wake of Hurricane Sandy and the Connecticut school shootings.
The Department of Education confirms Schools Chancellor Dennis Walcott sent a letter to principals Wednesday informing them of the new policy.
The letter says school leaders must also attend a two-hour training program over the summer, appoint staff members to response teams, and set up command posts.
The DOE says many schools are already conducting the drills.
During a lockdown, no one is permitted to enter or exit the school building.