BACKGROUND AND OBJECTIVES: Birth cohort screening for the hepatitis C virus (HCV) has been implemented in the US, but there is little evidence of its cost-effectiveness in England. We aim to evaluate the cost-effectiveness of one-time HCV screening for individuals born between 1950 and 1979 as part of the National Health Service health check in England, a health check for adults aged 40 to 74 years in primary care. METHODS: A Markov model was developed to analyze add-on HCV testing to the National Health Service health check for individuals in birth cohorts between 1950 and 1979, versus current background HCV testing only, over a lifetime horizon. The model used data from a back-calculation model of the burden of HCV in England, sentinel surveillance of HCV testing, and published literature. Results are presented from a health service perspective in pounds in 2017, as incremental cost-effectiveness ratios per quality-adjusted life years gained. RESULTS: The base-case incremental cost-effectiveness ratios ranged from £7648 to £24 434, and £18 681 to £46 024, across birth cohorts when considering 2 sources of HCV transition probabilities. The intervention is most likely to be cost-effective for those born in the 1970s, and potentially cost-effective for those born from 1955 to 1969. The model results were most sensitive to the source of HCV transition probabilities, the probability of referral and receiving treatment, and the HCV prevalence among testers. The maximum value of future research across all birth cohorts was £11.3 million at £20 000 per quality-adjusted life years gained. CONCLUSION: Birth cohort screening is likely to be cost-effective for younger birth cohorts, although considerable uncertainty exists for other birth cohorts. Further studies are warranted to reduce uncertainty in cost-effectiveness and consider the acceptability of the intervention.