Legitimately categorizing software in the healthcare sector is complex. According to European medical devices law, software can be considered a medical device. The decisive factor is whether the software is used for directly controlling a therapeutic or diagnostic medical device or as stand-alone software that achieves specific medical purposes, as they are described in the legal definition of a medical device. A contribution of the software to diagnosis or therapy can be sufficient for the categorization; it does not have to provide the complete diagnosis or the complete therapy itself.This principle will continue to be the same with the new Regulation on Medical Devices (EU) 2017/745, even though the classification rules have been more closely and more specifically tailored to software and more stringent requirements for essential safety and performance requirements have to be met.