The degradation of engineering materials poses a significant and ongoing challenge that limits their performance and longevity. The surrounding environment and mechanical loading strongly influence the degradation process, imposing distinct chemical, electrochemical, and biological driving forces. Among the various degradation mechanisms, corrosion, in its various forms, and stress corrosion cracking (SCC) are the primary mechanisms by which materials lose structural integrity. The synergistic effect of mechanical loading and aggressive environments reduces material degradation resistance, leading to crack initiation and premature failure, which can result in catastrophic incidents. The inherent multiscale nature of these two mechanisms and their interactions complicate assessing their impact on material and component performance. Computational modeling has become an effective approach for evaluating the degradation resistance of engineering materials and a valuable tool for component design to prevent failures. Multiphysics formulations based on the phase-field method have emerged as a promising technique for capturing complex dynamics of the metal-environment interface across multiple length scales and quantifying degradation kinetics, overcoming the long-standing obstacle of simulating environmentally assisted degradation, especially across different interacting time scales. This talk summarizes recent advances in phase-field modeling of material degradation, focusing on corrosion and microbiologically influenced corrosion in traditional engineering materials and biodegradable metals. The models capture different forms of corrosion and SCC across various length scales, from microstructural to macroscopic. Representative case studies of particular significance are explored to demonstrate the predictive capabilities of these phase-field frameworks. The talk also highlights opportunities for further advancements in the field.