Abstract. Model-based most specific concepts are a non-standard reasoning service in Description Logics. They have turned out to be useful in knowledge base completion for ontologies that are written in certain extensions of EL. There is indication that model-based most specific concepts can also be applied for knowledge base completion in other inexpressive description logics. We show that model-msc exist in the logics FL0 and FLE with cyclic TBoxes and for ALC with acyclic TBoxes. We provide constructions for model-msc in these three logics. Many of the ontologies that are used today are large in scale and formulated in one of the less expressive Description Logics (DL). As ontologies become larger, tools that support engineers during the process of building and maintaining ontologies are gaining in importance. Often, the people who are in charge of building an ontology are experts in the domain of interest, rather than experts in Description Logics. They may sometimes be unable to c...