How many days of school do you have to miss get held back?

There's no single answer to how many days of school you have to miss to get held back. It varies greatly depending on:

* School district policy: Each school district has its own attendance policy. Some are stricter than others.

* State laws: Some states have laws regarding minimum attendance requirements.

* Individual circumstances: Excused absences (doctor's appointments, family emergencies) are often treated differently than unexcused absences (truancy). A student with many excused absences might not be in danger of being held back, while a student with fewer unexcused absences might be.

* Student's academic performance: Even with perfect attendance, if a student is failing academically, they could be held back. Conversely, a student with some absences but excellent grades might still pass.

To find out the specific policy for a particular school or district, you need to check the school's attendance policy or contact the school administration directly.