Background: Participating in recommended levels of physical activity (PA) is critical for preventing functional decline, falls, and frailty, making it essential to identify older adults not meeting national PA guidelines. However, guidance on assessing older adult PA levels, particularly in clinical settings, is lacking. This article presents an overview of clinically feasible PA assessment tools for older adults, identifies gaps in current tools, and provides recommendations on addressing these gaps. Methods: We conducted a literature review on clinically feasible PA assessment tools, suggested modifications to an existing PA assessment for older adult patients, and highlighted opportunities for integrating the modified PA assessment tool in clinical settings. Results: We identified 16 PA assessment tools used in clinical settings. The most widely used tool is the Physical Activity Vital Sign (PAVS), which has been successfully integrated into several electronic health records (EHR) and clinical practices. Most tools, including the PAVS, primarily focus on aerobic activities, with limited consideration for strength and balance. We recommend the use of a Modified PAVS for Older Adults that includes items on muscle-strengthening and balance activities to better align with national PA guidelines. We then identified several existing opportunities for broad implementation of the Modified PAVS for Older Adults within clinical settings. Conclusions: Widespread integration of the Modified PAVS for Older Adults will better support healthcare providers in identifying individuals not meeting national PA recommendations, assisting them in prescribing tailored PA prescriptions and better connecting their patients to appropriate resources and professionals for further support. © 2024 The American Geriatrics Society.