This research project aims to better understand how P4P affects health facilities with different characteristics and achieves outcomes in Pwani region of Tanzania, where a pilot P4P scheme has been implemented since 2011. It will examine the effect of P4P on the functioning of accountability mechanisms within the health system, and on facility resourcing (drugs, supplies and equipment availability) and resource allocation. This will enable researchers to test possible mediation pathways through which P4P results in changes in outcomes.