This paper demonstrates why an increased quantity of funding as claimed by big health lenders is not effective to achieve Millennium Development Goal 6, stopping the spread of HIV by 2015. An alternative funding mechanism linking the disbursement of matching grants with a minimum provision level is suggested. In order to study the impact of conditional subsidies on the efficiency of international health-promoting public goods, non-cooperative multi-stage games are analyzed. In the participation stage, a subsidy which is contingent on some minimum provision level is determined. In later stages countries choose their contributions to a health-promoting public good and receive a subsidy if their supply is no less than a predetermined threshold. The analyses indicate that efficient provision levels can be achieved.