The measure, which paves the way for a five-year moratorium on school closings beginning in the fall of 2013, passed with an 84-28 vote in the House, before moving on to the Senate and passing with a 57-0 vote, according to WBEZ.
The legislation now goes to Gov. Pat Quinn.
Without the extension, officials would have had to announce the closings by Saturday.
Mayor Rahm Emanuel said in a statement that communities will have input in school-closure decision they haven't seen before from CPS.
"This additional time, in conjunction with the appointment of an independent commission to gather information and make recommendations, allows parents and community members to be brought into the discussion earlier in the process and more openly than before," he said in the statement.
CPS CEO Barbara Byrd-Bennett has said that the extension will allow for a transparent process that seeks community input.
Critics have said announcing closings in March does not provide enough time for people to voice opposition, and that the deadline is so close to the end of the school year that communities won't have enough time to prepare.
Byrd-Bennet announced Monday that CPS would implement a five-year moratorium on school closings starting in the fall of 2013.