C olorectal cancer (CRC) remains the second most common cause of cancer death in the United States. 1 However, CRC incidence and mortality have been decreasing over the past 4 decades, and screening has contributed substantially to these gains. 2-4 Screening aims to identify disease in asymptomatic individuals at an early stage, in the hope of improving outcomes. CRC lends itself very well to screening, as early-stage CRC has a highly favorable prognosis relative to more advanced disease. Also, the transition from normal mucosa through preneoplastic disease (ie, polyps) to CRC is estimated to be a decade or more. 5 Therefore, finding and removing preneoplastic lesions can reduce CRC incidence. Screening is widely employed in the United States, largely in an opportunistic fashion. While there is no national CRC screening policy or program, there are multiple guidelines endorsing CRC screening. 6-10 Most guidelines, in average-risk populations, recommend initiating CRC screening at age 50 years with one of the available methods. While there is some variation in recommendations by age and race, factors beyond these are not currently used to tailor individual recommendations. This review addresses current CRC epidemiology, screening practice, and guidelines in the United States, and considers how individual risk factors might be used to personalize CRC screening. We first summarize the burden of CRC and current screening efforts. Next, we examine current guidelines for variation regarding the approach to age, sex, and race, and we explain how decision analytic modeling has informed recent guidelines. We then review factors beyond demographic characteristics (eg, smoking, obesity) that affect CRC risk and provide potential opportunities for personalized screening, including the development of risk-prediction models that include biomarkers. Finally, we consider future directions for research and practice, including the opportunities and challenges related to implementing personalized CRC screening. Current Status of Colorectal Cancer and Screening in the United States The American Cancer Society (ACS) provides annual cancer statistics for the United States. 1 These statistics are drawn from a number of sources. For example, mortality data are abstracted from the National Center for Health Statistics, and cancer incidence data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program. The most recent ACS report estimates that there will be 145,600 new CRC cases and 51,020 CRC-related deaths in the United States this year. 1 CRC remains the third most common cause of cancer and cancer death for both sexes, trailing only lung and prostate cancer in men and lung and breast cancer in women. Age standardized CRC incidence and mortality trends in the United States are improving (Figure 1). From 1975 through 2015, overall CRC mortality fell from 28.1/100,000 to 14/100,000. 11 Like cancer statistics, data on screening are also drawn from various sources. Based on 2015 National Health Intervi...