CDSS-guided stewardship in six EDs during national culture bottles shortage was associated with significant reduction in median daily blood culture utilization per 1,000 ED visits from 141.5 (IQR:127.6–155.3) to 77.9 (IQR:68.3–86.3) and increased diagnostic yield from 6.2%(IQR:4.7%–7.6%) to 8.8%(IQR:6.1%–11.5%), without impacting length of stay or mortality.