Do Houston private schools require the ISEE?

Yes. Most highly selective Houston schools require the ISEE for all or most prospective students. Students looking to enter the school in 6th grade will take the ISEE Lower Level, students entering in 7th or 8th grade (non-gateway years) will take the ISEE Middle Level, and students entering in 9th grade (or later high school grades) will take the ISEE Upper Level. Some schools allow transfer students entering in 10th, 11th, or 12th grades (non-gateway years) to submit PSAT or SAT scores in lieu of ISEE scores.