The Clinical Quality Language (CQL) is the harmonized expression language for authoring eCQMs and CDS rules. When CQL is integrated into the MU program, it will replace all logic that is defined in the QDM (e.g., variables, temporal relationships, subset operators, specific occurrences, etc). QDM data types, however, will still be used (and referenced from CQL).

The QDM 5.0 specification should remove all specification of logical constructs, leaving only the QDM categories, data types, and attributes, for use with CQL. In place of the logic, the specification may wish to include a section on using QDM with CQL.