Deteriorating structures and infrastructure are continuously subjected to external loads, mechanical stressors, environmental conditions, and extreme events throughout their service life. These factors, highly uncertain in nature, complicate accurate assessment and prediction of structural performance and remaining service life. To address these challenges, timely inspection and monitoring are essential. However, inspection and monitoring alone cannot extend service life or improve performance. Thus, integrating inspection, monitoring, and maintenance management is crucial for the effective life-cycle management of deteriorating structures. This paper focuses on optimizing life-cycle inspection, monitoring, and maintenance planning, based on multiple objectives. These objectives include: (a) performance-based, (b) cost-based, (c) damage detection-based, (d) service life-based, and (e) risk-based objectives. In this paper, the formulations of these objectives and approaches for both single- and multi-objective optimization of inspection, monitoring, and maintenance management are presented. The decision-making process to select the best management strategy is provided. Furthermore, the updating process, leveraging information from inspection and monitoring, is addressed to enhance the accuracy of life-cycle inspection, monitoring, and maintenance planning.