This study aimed to systematically define the concept of“new -onset disability in older adults” using Rodgers’evolutionary concept analysis approach. Through a systematic literature search in both Chinese and international databases，34 articles were included for analysis. Five core attributes of new-onset disability in older adults were identified: sudden functional disruption，vulnerability in psychological adaptation，uncertainty of rehabilitation trajectories，discontinuity of caregiving resources，and time-sensitive nature of rehabilitation interventions. A conceptual framework was developed integrating multilevel antecedents（individual，family， community，societal）and multidimensional outcomes（physical，psychological，social）. A representative case was used to validate the recognizability and clinical applicability of this concept，revealing that the target population is situated in a critical transition period from functional independence to dependence，with substantial potential for recovery and intervention. This study fills a theoretical gap in the current literature and provides a scientific foundation for early identification，evidence-based intervention，and the optimization of health management strategies tailored to this high-risk aging population.