This research demonstrates the use of genetic programming to derive the objective function that ranks the candidate concepts and selects the set of best matching concepts for a sentence within medical text. A short set of example primitive and linguistic variables was input into the GP process, and a set of manually tagged sentences extracted from the literature was used to derive different objective functions potentially suitable for tagging. This proof-of-concept demonstrates the potential of this approach to simplify automated semantic tagging and to identify some of the likely challenges of applying the GP approach to complex linguistics problems of this nature.