Embodiments of the present invention enable processing of concept-based query requests submitted to a query service within a healthcare transaction framework. In embodiments, a terminology service within the healthcare transaction framework manages terminology content (concepts represented by a set of terminologies). In embodiments, search criteria from a data access query request are submitted to the terminology service to extract a set of concepts from the terminology content that are associated with the search criteria. In embodiments, equivalence search criteria include a seed concept, and the terminology service returns a set of equivalent concepts comprising the seed concept. In embodiments, classification search criteria include a classification identifier, and the terminology service returns a set of concepts associated with the classification identifier. In embodiments, the query service generates and submits a data access query comprising predicates associated with the returned set of concepts.