Why does dissociative personality structure persist long past the time when it was adaptive as a means of coping within a difficult early environment? If human beings were completely logical, we might expect that dissociative adaptations to a difficult childhood would diminish or discontinue when that child grows up and escapes that stressful world. But, for most adult dissociative clients, the separation between parts has continued long past the childhood time when it was created, when it was needed, and when it was adaptive. Why is this? In other words, what factors maintain the dysfunctional separation between dissociated personality parts, even long after the person has grown up and has been living in the larger adult world, perhaps for decades? This chapter provides a brief description on the persistence of dissociative personality structure and the internal healing dialogue procedure.