A manifestation determination is a special meeting that must happen before a school can remove a child with a disability from their placement for disciplinary reasons beyond a short period — generally when a removal reaches more than ten school days. The team, including you, meets to answer two questions: was the behavior caused by, or directly related to, the child's disability, and was it the result of the school failing to follow the IEP?
This protection exists so that children are not punished for behavior that flows from the very disability the school is supposed to be supporting. If the team decides the behavior was a manifestation of the disability, the child generally cannot be disciplined the same way a non-disabled peer would be. Instead, the team looks at the behavior plan and supports, and usually the child returns to their placement.
As a parent, this meeting is important to attend and prepare for. Bring what you know about your child's disability and how it shows up in behavior, and any history the team should weigh. If the team decides the behavior was not related to the disability, you can disagree — and you have the right to appeal that decision through due process, with stay-put protections that differ in discipline cases.
General information and document preparation — not legal advice.