OBJECTIVES:  The application of health technology assessment (HTA) to medical devices and diagnostics is now a reality. Hospital-level HTAs for medical devices are becoming more sophisticated and rigorous with the understanding that the individual dynamics of the hospital system may vary from the national perspective. Additionally, there is recognition that devices & diagnostics need to be evaluated differently from drugs and HTAs focused specifically on device and diagnostics are becoming more common. This analysis sought to identify the factors impacting the likelihood and impact of an HTA for medical devices and diagnostics across target markets. METHODS:  Extensive secondary research was performed in 10 emerging and developed countries, focusing on HTA process, availability of specific guidance for medical device and diagnostic products, criteria used for evaluations, stakeholders involved (including role of patients), and HTA jurisdiction (local, regional, national). We then categorized the countries according to the factors likely to impact HTA for medical devices and diagnostics across target markets. RESULTS:  The likelihood of a medical device receiving an HTA in any country is dependent upon (1) regulatory requirements for market entry; (2) health system impact; and (3) sophistication and reach of HTA body. Funding systems will impact the likelihood of whether the HTA is hospital-based or national. The most likely reason for negative assessments or inability to achieve premium pricing is due to insufficient clinical evidence and a need for head-to-head trials showing superiority to current care. CONCLUSIONS:  Medical device and diagnostic manufacturers are being challenged to do a better job at communicating value and designing studies to meet the needs of more stringent reviews. This research highlights countries and scenarios where HTA is likely to have an impact and provides suggestions on how to best navigate the diverse requirements.