Three Hamilton County schools and three Bradley County schools are among those impacted by a TNReady scoring error.
State education officials believe nearly 10,000 assessment tests across the state were scored incorrectly.
In Chattanooga, Red Bank High School, Lookout Valley Middle/High and Ivy Academy were affected, according to school officials.
In Bradley County, the schools affected were Bradley Central High School, Walker Valley High School and Bradley County Virtual School, Linda Cash, director of schools, said in a statement.
The only subject effected was Integrated Math 2. The scoring error involved 402 students but only 55 students had corrections that changed their performance levels.
Nine teachers were impacted by the recent events and school officials are waiting for the revised TVAAS scores to see if the changes were significant enough to make a change in the teachers' individual growth score.
The district will also be reviewing revised accountability data at the teacher, school and district level for growth and achievement.
About 9,400 of the approximately 600,000 TNReady tests that were taken in the last school year were incorrectly scored, according to The Commercial Appeal, a Memphis, Tenn., newspaper.
Once the errors were corrected, officials say about 1,700 of those 9,400 incorrectly tallied tests actually ended up with a different overall score.
State department of education spokeswoman Sara Gast said the errors did not affect the statewide results.
Because TVAAS teacher assessment scores partially rely on student test results, the scores for about 230 educators statewide will need to be recalculated.
"Questar takes responsibility for and apologizes for this scoring error," Questar Assessment, the company that administers and scores TNReady tests, said in a statement. "We are putting in additional steps in our processes to prevent any future occurrence. We are in the process of producing revised reports and committed to doing so as quickly as possible."
Gast said the scores are due to Questar incorrectly updating its scanning software.
List off affected districts, according to Chalkbeat: