It means all remaining primary school students and 5th years at second level will return to class next Monday.
The Department of Education wrote to schools this afternoon informing them the next wave of re-openings can go ahead next Monday.
That will see the return of third to sixth class in primary schools, and fifth years in secondary schools.
The letter says public health officials have reviewed the measures in place around the existing re-opening and are satisfied if they're stuck to that it's safe to continue the phased plan.
It also reminded principals that unnecessary travel should be avoided and to remind parents and students not to congregate at the school gates or in the grounds.
Health officials have only had one week of re-opening data to analyse before coming to their decision to continue with the phased plan next week.
More data is due to be released on the number of cases in schools, but officials have decided it's low enough to allow hundreds of thousands more students to return to the classroom.
The remaining students, from 1st to 4th year in secondary school, will still be waiting until after Easter to get back into the classroom.