Hepatitis C virus (HCV) infection is a substantial and largely unrecognized public health problem. An estimated 3.5 million persons in the United States are currently living with HCV infection, at least half of whom are unaware of their infection (1-3). Persons born during 1945-1965 (the "baby boomer" birth cohort) have a sixfold higher prevalence (2.6%) than adults of other ages, and represent 81% of all persons chronically infected with HCV (4). Therefore, in addition to recommending testing for all persons at risk for HCV infection, CDC and the U.S. Preventive Services Task Force (USPSTF) recommend one-time HCV testing for the birth cohort (5,6). Compared with the national average, American Indian/Alaska Native (AI/AN) persons have approximately twofold the rate of acute HCV incidence and HCV associated mortality (2). In June 2012, the Indian Health Service (IHS) implemented HCV testing in the 1945-1965 birth cohort and created a nationally standardized performance measure to monitor implementation of the recommendation. As of June 2015, the proportion of the birth cohort screened for HCV increased from a baseline of 7.9% (14,402/182,503) to 32.5% (68,514/211,014) among the AI/AN population served by IHS nationwide; provider training and the use of clinical decision tools were associated with increases in HCV testing. With this fourfold increase in testing in just 3 years, IHS needs to prepare for the challenges associated with increased identification of persons living with HCV infection.