ABSTRACT The red, yellow, and green three-colored health code apps (HCAs) have been credited as an effective tool for the COVID-19 response in China, with a golden color added indicating vaccination status in spring 2021. Although the success of HCA as a public health intervention might have legitimized government or corporate surveillance, the scope and contour of post-pandemic HCA use remain unclear. Both officials and tech firms have been promoting broader post-pandemic HCA use for purposes beyond pandemic control. This research draws on theories on privacy, trust, and media engagement to investigate factors affecting Chinese public opinion on HCA's post-pandemic use. Original survey data were collected in 2021 from adult HCA users in two major Chinese cities: Wuhan where COVID-19 cases were first identified and Hangzhou where the first HCA was deployed. Results point to a majority for moderate post-pandemic HCA use, while almost four out of ten users support expansive HCA use and the voice for restricted or terminated use is tiny. Greater acceptance of HCA data use by various institutional stakeholders, greater institutional trust, greater engagement with COVID-19 related social media content increased the support for expansive use.