This study is a retrospective chart review of standardized outcome measure data assessing mobility in persons with lower-limb loss. Patient charts were reviewed after the recent adoption of outcome measures as standard practice at a multiregion prosthetic practice. The study investigated the effects of amputation level and assigned activity level (K-level) on patient-perceived potential for mobility and functional ambulatory potential. The Amputee Mobility Predictor (AMP) and Prosthesis Evaluation Questionnaire–Mobility Subscale (PEQ-MS) scores were obtained and compared between transtibial and transfemoral patients and stratified by K-level. An analysis of variance (ANOVA) of AMP and PEQ-MS scores yielded significant variation (a = 0.05) for amputation K-levels. A Fisher protected least significant difference post hoc test found that the K3 and K4 groups had significantly higher AMP with prosthesis (AMPPRO) and PEQ-MS scores than those of the K2 group. The AMP and PEQ-MS scores were not found to be significantly different among transtibial and transfemoral amputation levels in the population studied. These two outcome measures have shown promise for differentiating K-level when adopted as standard practice in the clinical setting.