Education: facilities; requirements concerning restrooms and other certain areas in public schools; modify. Amends 1976 PA 451 (MCL 380.1 - 380.1852) by adding sec. 1146a.

SB 9 requires Michigan public schools to restrict access to multiple-occupancy restrooms and changing areas (like locker rooms or showers) based solely on biological sex, defined as the sex listed on a person's original birth certificate. Exceptions allow use by individuals entering for custodial, maintenance, medical, or caregiver purposes (including parents or authorized caregivers), or when temporarily designated for their biological sex. The bill directly affects public school students and staff by mandating gender-based restroom access in shared facilities. It modifies existing school code to establish this requirement, with specific definitions clarifying terms like "biological sex" and "multiple-occupancy area." The law does not apply to single-stall restrooms or facilities not designed for multiple users at once.