National Trends in Emergency Department Boarding and Interfacility Transfers by Rurality.

Emergency department (ED) boarding negatively impacts patient care nationwide. Rural hospitals are uniquely challenged as ED volumes increase despite declining inpatient capacity. Interfacility transfers are a growing component of rural ED operations and remain underexamined in evaluation of ED boarding. This study assessed trends in ED boarding and interfacility transfers by rurality. We conducted a repeated cross-sectional analysis using National Hospital Ambulatory Medical Care Survey (NHAMCS) data from 2001 to 2022 and a health system from 2019 to 2025. Outcomes included (1) yearly ED boarding proportions stratified by disposition and rurality and (2) yearly interfacility transfer proportions by rurality. We defined rurality using Metropolitan Statistical Area and Rural-Urban Commuting Area codes. Results were further stratified by medical and behavioral health patients. National ED boarding increased from 5.1% in 2001 to 11.3% in 2022, significant in urban (annual percentage change [APC] 5.3%, 95% CI 3.8%-6.8%) and rural (APC 9.1%, 5.1%-13.1%) hospitals. Health system ED boarding increased from 4.1% in 2019 to 10.8% in 2025, significant in urban (APC 13.6%, 7.1%-20.6%) and rural (APC 31.2%, 16.3%-48.1%) hospitals. ED boarding was highest for behavioral health transfers and increased significantly in rural health system hospitals. Health system medical transfer ED boarding increased faster in rural hospitals (p = 0.002), and annual medical transfer proportions were higher in rural EDs. ED boarding is increasing nationally. Rural transfer proportions exceed that of urban EDs and are an overlooked component of rural ED boarding. These findings have important policy implications with recent reimbursement changes and national boarding quality measures.