The tentative agreement will be voted on by the CTU's House of Delegates as part of the union's review process, according to CPS.
"In-person learning will resume for high school students for the first time in more than a year, and for the first time since March 2020 students in all grade levels at CPS have access to in-person learning," Mayor Lori Lightfoot and CPS CEO Dr. Janice Jackson said in a statement.
"It is a critical milestone for our families and it's a tremendous step forward for the academic and social-emotional well-being of our students," the statement said.
In-person learning for high schoolers has been paused since the coronavirus pandemic sent students home for remote learning in March 2020.
The CTU House of Delegates will hold a special meeting Thursday at 4:30 p.m. to review and consider the recommendation from its rank-and-file high school steering committee, CTU said.
BREAKING: We have a tentative framework with CPS for a return to in-person instruction for high school students. The CTU House of Delegates is holding a special meeting today at 4:30 p.m. to review and consider the recommendation from our rank-and-file h.s. steering committee.— ChicagoTeachersUnion (@CTULocal1) April 15, 2021
The announcement comes after teachers held a teach out Thursday morning after refusing to report to work for a second day.
"We have pandemic fatigue too, but we are not willing to sacrifice the lives of our students and their families because we're tired and we want to get back to normal," said Jackson Potter, Back of the Yards College Prep teacher.
The teachers union and school officials have been locked in negotiations over a reopening plan for students ahead of Monday's start date. However, the union is worried about a new uptick in cases, especially among young people.
High school teachers in Chicago Public Schools were back to working remotely starting Wednesday.
High school students should not notice any difference, as teachers will continue to teach, albeit from their living rooms rather than from their classrooms, where they have been already the last two days, preparing for the return to in-person learning still scheduled for Monday.
However, it is still unclear if that return will take place.
CTU officials updated their membership late Tuesday, after a long day of negotiations, saying some progress had been made at the bargaining table, but no agreement has been reached just yet.
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Modified work schedules that allow students in higher-density schools to attend only once a week, remote work for teachers who will continue to teach virtual students and a firm commitment to vaccinate eligible students and their families are among the details to be ironed out.
"Four areas that we think are extremely reasonable, where right now the board just hasn't gotten to 'yes,'" CTU President Jesse Sharkey said. "We want to be back in school."
And while a recent survey conducted by Chicago Public Schools shows only 44% of high school parents want their children to return to in-person learning, a vocal group of them gathered outside CTU headquarters Tuesday.
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"CTU, stop the delays and focus on education solutions for our children," said Nancy Griffin, with the Chicago Parents Collective. "CPS, all we're asking for is that next week, on April 19th, as planned, our high schoolers can put on their backpacks and walk into the classrooms that they've been missing for over a year. They need it. We need it. The community needs it. Chicago needs it."
The district meanwhile continues to say progress is being made in all areas, and remains fully committed to reopening school buildings next week.
As of now, only one in four of Chicago's public high school students are slated to return on Monday.
Sun-Times Media contributed to this report.