BACKGROUND: Community-acquired pneumonia (CAP) remains a leading cause of hospital admissions and mortality. A novel host-response test, MeMed BV (MMBV), has been developed for discriminating between bacterial and viral infection that could improve the clinical management of CAP. OBJECTIVES: To evaluate the cost-effectiveness of using MMBV to guide antibiotic decisions in the clinical management of CAP in the UK. METHODS: An economic model was developed to understand the incremental cost per person associated with the implementation of MMBV from the UK NHS perspective. A qualitative care pathway analysis was performed to inform the standard of care (SOC) and SOC plus MMBV (SOC + MMBV) clinical pathways captured in the model. RESULTS: In the base case analysis, the SOC + MMBV strategy for a hypothetical cohort of 1000 patients (adults and children modelled independently) presenting to the emergency department with suspected CAP was estimated to provide total cost savings of £134 018 and £105 750 for adults and children, respectively. Cost savings were associated with reductions in total antibiotic treatment, the number of patients receiving additional diagnostic tests, and hospital admissions. Deterministic sensitivity analysis revealed that the specificity of SOC + MMBV and sensitivity of the SOC were primary drivers of the cost model for adults, whereas the specificity of SOC and SOC + MMBV were primary drivers for paediatrics. CONCLUSIONS: Overall, the model predicts that the introduction of SOC + MMBV has the potential to be cost-saving and promote antimicrobial stewardship for both adult and paediatric CAP patients.