Verification in results-based financing (RBF) mechanisms is one of the key differentiators between it and related health financing structures such as social health insurance. Verifying that providers have achieved reported performance in RBF mechanisms is considered a crucial part of program implementation and key to maintaining trust through transparency, as well as the viability of the mechanism. Verification is however a process which has thus far been little studied. Information on the methodologies used in different settings (including frequency and sampling methodology), the effectiveness of the verification process, the direct and tangential effects, and the cost is scarce. Plan Nacer employs one of the largest RBF mechanisms in the world and is therefore an excellent case study for the role, methodology and effects of the verification process. This study will give the background to Plan Nacer, detail the major characteristics of the verification process and draw lessons on the process which can inform the design of verification in RBF mechanisms in other countries.