Tennessee Investment in Student Achievement (TISA) - As introduced, revises the weighted allocations generated by a student for purposes of the TISA based on the number of student members of the LEA in which the student resides; establishes a $50 direct allocation for each student member of each LEA to assist each LEA with maintenance and infrastructure. - Amends TCA Title 49, Chapter 3.

HB 9 revises Tennessee's K-12 school funding formula (TISA) to adjust weighted student allocations based on school district size and add a direct infrastructure grant. It changes funding percentages for districts of different sizes (e.g., districts with 1,000-1,999 students now receive 4% instead of previous rates) and establishes a $50 direct allocation per student for school maintenance and infrastructure. This affects all Tennessee public school districts (LEAs) and their students, applying to the 2025-2026 school year and beyond. The bill does not change overall funding levels but redistributes existing resources based on district size and adds the per-student infrastructure grant.