Chronic HCV infection is a non-traditional (but modifiable) risk factor for chronic kidney disease and has been implicated in glomerular injury and nephrosclerotic disease. Three HCV direct-acting antiviral regimens are available for patients with severe kidney impairment: ombitasvir, paritaprevir with the pharmacokinetic enhancer ritonavir, and dasabuvir; glecaprevir plus pibrentasvir; and elbasvir plus grazoprevir. In patients with severe kidney impairment, sofosbuvir-free regimens are preferred because sofosbuvir accumulation has been associated with a progressive worsening of renal function. In this Review, we provide our expert opinion on the current HCV treatment paradigm and highlight the remaining issues that need to be overcome to improve the treatment of HCV in this population. Incidence of CKD in patients with HCV infection The stages of CKD as defined by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines range from normal (CKD stage 1) to kidney failure (CKD stage 5) and are described in Table 1 [7]. Until recently, data regarding the prevalence of CKD in patients with hepatitis C were limited. In HCV-positive patients, the prevalence of low glomerular filtration rate (GFR <60 ml/min/1.73 m 2) is reported to range from 5.1 to 17.2% [8-10], and the prevalence of renal insufficiency (serum creatinine ≤1.5 mg/dl) is 4.8% in US veterans [11]. In patients coinfected with HIV and HCV, the unadjusted frequency of low GFR (30-59) ranged from 3.7 to 4% [12]. Based on the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) modified guidelines [13], the prevalence of CKD was significantly greater among patients with detectable HCV RNA compared with age-, race-and gender-matched anti-HCV-negative controls (9.1% versus 5.1%; P<0.04) [14]. According to data from the Chronic Hepatitis Cohort Study, the prevalence of estimated (e)GFR <80 ml/min/1.73 m 2 was 33% and eGFR <30 ml/min/1.73 m 2 was 2% in patients with HCV infection, including those with hepatic fibrosis [15].