No Child Left Behind Improvement Act of 2006

No Child Left Behind Improvements Act of 2006 - Amends the Elementary and Secondary Education Act of 1965 to alter requirements for adequate yearly progress (AYP) assessments of student groups by: (1) lowering, from 95% to 90%, the minimum percentage of students in each group in a school that must take such assessments; (2) allowing the fractional counting of students who are in more than one group, for each such group; (3) allowing states to treat as proficient or advanced specified scores on alternate assessments for disabled students and those not proficient in English; and (4) allowing states to use alternative methods of defining AYP.

Revises criteria for local educational agency identification of schools needing improvement. Declares that only those meet such criteria that fail AYP standards, for two consecutive school years (as under current law), in the same subject for the same group of students.

Revises eligibility criteria for school transfers after a school is identified as needing improvement. Declares that only failing students in the failing group, instead of all students in such a school, may transfer. Allows such schools to provide students with supplemental services rather than transfers during that school year.