Under the Right to Education Act (2009), the Indian government mandated private schools to reserve 25% of primary school places for socioeconomically disadvantaged children. This study examines the policy’s spillover effect on private schooling costs. Using household survey data and a difference-in-differences approach, it compares private school fees for disadvantaged children across two age cohorts and survey rounds. Findings show fees decreased by ₹223–₹844 (0.05–0.25 SD) post-policy. A 5% enrolment increase led to a fee reduction of ₹240–₹470 (0.05–0.14 SD). The effects are driven by an increased supply of low-fee private schools facilitating cheaper private education for disadvantaged children.