This report provides updated recommendations for selecting the bandwidth parameter when mapping mean utility values from EQ-5D-3L to EQ-5D-5L using the EEPRU reference case mapping model. We calibrate the bandwidth rules using three datasets: FORWARD, UKHLS Innovation Panel, and the EEPRU dataset. These datasets encompass a range of health conditions and population groups. The report evaluates the performance of previous guidance from the NICE Decision Support Unit which was based on the only available dataset at the time, the FORWARD dataset, and proposes a simplified bandwidth rule that ensures smooth and monotonic mappings across the full spectrum of health states. This recommendation is intended to support analysts using the eq5dmap tools in R, Stata, and Excel for health economic evaluations.