Infection prevention barrier precautions provide a foundation for infection prevention practices that span the spectrum of healthcare settings. Modern healthcare delivery has expanded from the traditional hospital to other settings that include home care, ambulatory care, freestanding specialty care sites, and long-term care. Having a standardized approach to barrier precautions, also referred to as isolation precautions, both simplifies and unifies the actions that healthcare personnel take, regardless of the setting. The 2007 Guideline for Isolation Precautionshas several features that older guidelines lack, including the addition of several newer diseases and emerging pathogens, as well as describing techniques to prevent transmission in home care and ambulatory care. The goals of this chapter are to provide an overview of the isolation guidelines published in 2007 by the Healthcare Infection Control Practices Advisory Committee and the Centers for Disease Control and Prevention to address the emergence of new pathogens and concern for evolving pathogens, and to examine practical and effective ways to control the spread of multidrug-resistant organisms. The reader can access the document 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settingsat http://www.cdc.gov/hicpac/2007IP/2007isolationPrecautions.html. Additional guidelines and references pertaining to isolation and prevention of infectious agents are listed in the Supplemental Resources section of this chapter.