Techniques are described to allow the deprecation of classes in an object-oriented data model, such as a CDM for a CMDB. When a class is deprecated and replaced by another existing or new class, data associated with instances of the deprecated class may be migrated to the replacement class. A mapping between the deprecated class and its replacement class may be provided to allow existing applications to continue to access data using the deprecated class without change until the deprecated class is finally deleted or the application is updated to use the replacement class. New applications written to use the object-oriented data model after the deprecation may use the replacement class to access data instances created using the original data model.