The fact that special can be "sort of" to "very" special—that special education exists on a continuum—has been used in arguing that general and special education can, should, or must be merged. Some education reformers have seized upon it as a way of explaining how all students, without exception, can be accommodated in general education with no need for any special classes or schools. In traditional education, for a bit over a century there have been essentially two "tiers" of education: general education and special education. And within that second tier there have been what might be called "sub-tiers" of different levels of integration into general education, for example, general education classroom with supplemental special education (such as consultation), resource room, self-contained classroom, special education day school, special education residential school. The chapter discusses the three frameworks—representing instruction or intervention (RTI), multi-tiered systems of supports (MTSS), and positive behavioral interventions and supports (PBIS).