Three years of national survey data (2000, 2002, and 2004) were used to examine the scope of services offered by Critical Access Hospitals (CAHs). The authors investigated how the services offered by CAHs have changed, the role of network affiliations in these changes, and the reasons administrators gave for reported service expansions. Additionally, the authors looked at how services in CAHs have changed over time. Consistent with findings in previous surveys conducted by the Flex Team, conversion to CAH status has not led to downsizing of services. Most CAHs offer a core set of services including radiology, laboratory services, emergency rooms, swing beds, pharmacy, outpatient rehabilitation, outpatient surgery, and specialty clinics. While this core has not changed significantly over the period of three surveys, many CAHs have added or expanded services not dependent on inpatient capacity Report produced by the Flex Monitoring Project, funded by the Office of Rural Health Policy.