According to a recent review of Legionnaires' disease outbreaks, 34 percent were associated with long-term care facilities and hospitals. Patients at risk of contracting Legionnaires' disease include smokers, those with compromised immune systems and other chronic conditions. Exposure typically occurs through Legionella-contaminated water that is aerosolized through showerheads, cooling towers, hot tubs and decorative fountains.

Effective June 2, 2017, the Centers for Medicare & Medicaid Services (CMS) of the U.S. Department of Health & Human Services issued a requirement for Medicare-certified healthcare facilities to reduce the risk of Legionella bacteria in their water systems to prevent Legionnaires' disease. Citing an American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) industry standard, CMS requires the facilities to "have water management policies and procedures to reduce the risk of growth and spread of Legionella and other opportunistic pathogens in building water systems." Facilities that do not have policies, procedures and reports to document the water management implementation will risk a citation for non-compliance with the CMS Conditions of Participation.