Health policies and the problems they constitute are deeply shaped by multiple publics. In this article we conceptualize health policy counterpublics: temporally bounded socio-political forms that aim to cultivate particular modes of conduct, generally to resist trajectories set by arms of the state. These counterpublics often emerge from existing social movements and involve varied forms of activism and advocacy. We examine a health policy counterpublic that has arisen in response to new forms of HIV public health surveillance by drawing on public documents and interview data from 2021 with 26 stakeholders who were critical of key policy developments. Since 2018, the national rollout of molecular HIV surveillance (MHS) and cluster detection and response (CDR) programs in the United States has produced sustained controversies among HIV stakeholders, including among organized networks of people living with HIV. This article focuses on how a health policy counterpublic formed around MHS/CDR and how constituents problematized the policy agenda set in motion by federal health agencies, including in relation to data ethics, the meaningful involvement of affected communities, informed consent, the digitization of health systems, and HIV criminalization. Although familiar problems in HIV policymaking, concerns about these issues have been reconfigured in response to the new sociotechnical milieu proffered by MHS/CDR, generating new critical positions aiming to remake public health. Critical attention to the scenes within which health policy controversies play out ought to consider how (counter)publics are made, how problems are constituted, and the broader social movement dynamics and activist resources drawn upon to contest and reimagine policymaking in public life.