Verification in results-based financing(RBF) mechanisms is one of the key differentiators betweenit and related health financing structures such as socialhealth insurance. Verifying that providers have achievedreported performance in RBF mechanisms is considered acrucial part of program implementation and key tomaintaining trust through transparency, as well as theviability of the mechanism. Verification is however aprocess which has thus far been little studied. Informationon the methodologies used in different settings (includingfrequency and sampling methodology), the effectiveness ofthe verification process, the direct and tangential effects,and the cost is scarce. Plan Nacer employs one of thelargest RBF mechanisms in the world and is therefore anexcellent case study for the role, methodology and effectsof the verification process. This study will give thebackground to Plan Nacer, detail the major characteristicsof the verification process and draw lessons on the processwhich can inform the design of verification in RBFmechanisms in other countries.