Cancer screening has increased dramatically in the United States, yet in some populations, particularly racial minorities or the poor, advanced disease at diagnosis remains high. One potential explanation is that follow-up of abnormal tests is suboptimal, and the benefits of screening are not being realized. The authors used a conceptual model of access to care and integrated constructs from models of provider and patient health behaviors to review published literature on follow-up care. Most studies reported that fewer than 75 percent of patients received some follow-up care, indicating that the promise of screening may be compromised. They identified pervasive barriers to follow-up at the provider, patient, and health care system levels. Interventions that address these barriers appear to be effective. Improvement of data infrastructure and reporting will be important objectives for policy makers, and further use of conceptual models by researchers may improve intervention development and, ultimately, cancer control.