Although Decision Support Systems (DSS) play a dominant role in organizing data and models, its capability in supporting decision makers in collaborating distributed environments is still limited when it comes to the selection, sharing, and re-use of models. For mathematical models to be shared and reused, mechanisms are needed for understanding, implementing, modifying, discovering, selecting, engaging, and composing models. At a fundamental level, model representation will need to extend beyond model structure to include model semantics as well. This research leverages advances in Semantic Web technologies and ontologies to enable sharing and re-using of decision models by providing enriched semantics in collaborative decision making environments. The proposed approach builds on structured modeling (SM) as an underlying modeling formalism and is illustrated using the Web Ontology Language (OWL). A case study demonstrates the viability of the approach for capturing model semantics models using ontologies.