OBJECTIVES: Regular glucose monitoring is important for T1DM patients receiving intensive insulin. A novel, factory-calibrated flash continuous glucose monitoring system (the FreeStyle Libre™ system) continuously measures glucose levels from interstitial fluid. Data transfers to a handheld reader from a wearable arm sensor without requiring routine self-monitoring of blood glucose (SMBG). The IMPACT RCT (Bolinder 2016) showed reduced time spent in hypoglycemia in T1DM for the flash monitoring system compared to SMBG, while decreasing the number of blood glucose tests by 91%. A time trade-off study demonstrated a utility benefit with the flash monitoring system compared with SMBG (Matza 2015). This analysis assesses the cost-effectiveness of the flash monitoring system versus SMBG in T1DM patients receiving intensive insulin from a UK NHS perspective.  METHODS: The IMS Core Diabetes Model was run over a 50-year lifetime horizon, modelling a population reflecting the IMPACT study. Intervention effects included study-based reductions in hypoglycemic events (glucose <70mg/dL; 25.5% fewer daytime events, 33.2% fewer nocturnal events), and the utility benefit (0.03; Matza 2015). Costs are reported in 2015 GBP. Incremental cost-effectiveness ratios (ICERs) were calculated, with sensitivity analyses conducted for key inputs. RESULTS: The base case ICER was £25,045 and cost per hypoglycemia event averted was £27. For the scenario analyses, ICERs ranged from £7,643 to £30,811. CONCLUSIONS: Improved hypoglycemia and a health utility benefit translate to a base case ICER under the NICE threshold for cost-effectiveness for medical devices of up to £30,000 per QALY. This result was confirmed across a range of scenario analyses. The flash monitoring system may be considered cost effective for use in the UK NHS for T1DM patients receiving intensive insulin.