The are countless references to the development of a new phase of life between childhood and adulthood (referred to as post-adloscence) in the technical literature of sociology. Different theoretical models have been developed in sociology to interpret postadolescence. After the discussion of the models, a new model is indruced in this contribution. The forms and "timing" determining how and when young people leave their parents' house house regarded as the most important consitutive characteristic of the postadolescent phase in this model. It is thereby assumed that this detachment from the parents' house is regarded as the most important consitutive characteristic of the postadolescent phase in this model. It is thereby assumed that this detachment from the parents' house is dependent upon surrounding macro-structural social conditions. In this model, the following detachment dimensions are regarded as significant: legal dimension, household dimension, economic-fianacial dimension, social dimension, emotional dimension. The analysis of the process of detachment based upon these dimensions reveals that postponed partial detachment, succesive detachment, and reversibile detachment are all consitutive elements of post-adolescence. The fact that young people who have reached legal adulthood remain in many respect dependent upon their parents, remains an important facet of post-adolescence. The analysis also reveals that post-adolescence cannot be clearly defined based upon the criteria of age , with regard to "youth or "adulthood". It is therefore an empirical question who and how many members of a specific age category of young adults (i.e. 20-25 years or 30 year olds) find themselves in the post-adolescent phase according to the theoretically proven criteria.