The One Health Assessment for Planning and Performance (OH-APP) is a monitoring framework for multisectoral coordination mechanisms (MCM) to annually self-assess their organizational capacity and performance to inform planning and development assistance. The OH-APP complements the WHO Joint External Evaluation by providing more specific indicators to measure the maturity of an MCM and benchmark its progress toward becoming a sustainable mechanism capable of coordinating multisectoral and multistakeholder collaboration for preparedness and response to public health threats.