The 600 plus school districts suing Texas say the way the state pays for public education is "constitutionally and fundamentally broken."
State District Judge John Dietz declared more than a year ago that funding for public education is inadequate and unfairly distributed among school districts.
The initial decision came in response to the Legislature's cutting $5.4 billion in funding to classrooms in 2011. But last year, lawmakers restored more than $3.4 billion while easing high school graduation standards.
Dietz reopened the case three weeks ago to hear evidence on how that might affect his initial decision.
During closing arguments Friday, school district attorney Rick Gray said "Band-Aid solutions" aren't enough.
Dietz will issue a final, written ruling on the entire trial after mid-March. That will be appealed to the Texas Supreme Court.