This study investigates the impact of digital exclusion among vulnerable groups in social protection programs. It argues that digital identity systems are capable of exarcerbating inequalities in societies characterised by poverty and vulnerability. We use the lens of adverse digital incorporation to draw on two social protection programs, Bolsa Familia in Brazil and the Public Distribution System in India, both of which have been augmented with digital identity systems. Our qualitative data reveal that digital identity systems can generate justice only if existing processes of adverse digital incorporation are acknowledged and digital systems are framed to tackle design, resource, relational, and institutional inequalities. Drawing from development studies and data justice literatures, we show the importance of infusing justice in digital identity systems to build fair and effective social protection programs.