Two mold remediation companies were hired to give the 600, 700 and 800 wings of the school a deep cleaning.
The School District of Indian River County says testing reports indicate satisfactory results for the affected wings.
Teachers and staff spent Wednesday afternoon moving back into that part of the building.
Parents are still allowed to keep their kids home this week. Excused absences will be offered all week.
Despite the reopening of these classrooms, early release schedules remain in effect, which is 1:40 p.m.
Free before and after school care is still being offered to students.
The district is still awaiting mold test to come back for two addition wings. If parents decide to send kids to school who correspond to those area, they will still be accepted but taken to alternate, safe areas.