No Child Left Behind Flexibility and Improvements Act

No Child Left Behind Flexibility and Improvements Act - Amends the Elementary and Secondary Education Act of 1965 (ESEA), as amended by the No Child Left Behind Act of 2001, to revise requirements relating to annual yearly progress (AYP) of students and schools, statewide and local accountability systems, special education, limited English proficiency students, funding levels and academic assessment deferrals, highly qualified teachers, and reading activities.

Authorizes the Secretary of Education to modify an AYP timeline.

Allows states to use: (1) additional types of statewide models and systems for measuring all students' progress; and (2) alternative assessments, designated by their individualized education program plan teams, for students with disabilities.

Gives states an option to include as limited English proficiency students, until they complete secondary school, those formerly in such subgroup who have subsequently acquired English proficiency.

Permits use of local assessments in measuring AYP.

Increases the levels of ESEA funding which must be reached before states are not allowed certain deferrals of academic assessments.

Revises requirements relating to AYP by group and subgroup.

Adds options for deeming teachers of multiple academic subjects as highly qualified, and for general social studies certification.

Authorizes use of reading activities subgrants for individual or small-group instruction, as well as for class-wide instruction.