Public providers have no financial incentive to respect their legal obligation to exempt the poor from user fees. Health Equity Funds (HEFs) aim to make exemptions effective by giving NGOs responsibility for assessing eligibility and compensating providers for lost revenue. We use the geographic spread of HEFs over time in Cambodia to identify their impact on out-of-pocket (OOP) payments. Among households with some OOP payment, HEFs reduce the amount paid by 35%, on average. The effect is larger for households that are poorer and mainly use public health care. Reimbursement of providers through a government operated scheme also reduces household OOP payments but the effect is not as well targeted on the poor. Both compensation models raise household non-medical consumption but have no impact on health-related debt. HEFs reduce the probability of primarily seeking care in the private sector.