Currently, there is a lack of clarity as to how new molecular diagnostics can navigate the development ‘pathway’ and go from discovery and research into routine clinical practice. Compared with therapeutics, the development pathway for diagnostics is more complex and fragmented, leading to low uptake. At the end of the current pathway, regulatory organisations such as NICE in the UK often have to assess diagnostic technologies without robust ‘end-to-end’ studies demonstrating the full impact on patient benefits and costs. Where significant evidence gaps exist, assessment by NICE can often prove a challenge with promising technologies failing to secure positive recommendations as a result. Unlike therapeutics, implementation within the NHS for NICE-approved diagnostics is not mandatory, leading to further uncertainty for developers as to whether there is a return on investment. A clear and explicit description of the diagnostic pathway and the role of economic evidence could help to (1) improve research efficiency by informing the identification and collection of appropriate data earlier in the development process; (2) identify methodological work needed to improve the rigor of such research; and (3) align evidence generation to the needs of local and national decision-makers. The objective of this conceptual study is to describe a ‘map’ of the current development pathway for new diagnostic technologies within England and Scotland and describe the type of economic evidence needed to support the development process at each defined stage of the pathway. Drawing upon the collective experience of health economists working within the UK diagnostics landscape, the pathway will differentiate between types of diagnostics (e.g. ‘companion’ versus ‘standalone’) and delineate the differences between evidence generation and assessment for diagnostics compared with therapeutics. The different types of economic evidence required by NICE and local funders will also be discussed and the implications for likely implementation highlighted.