Objective: There have been recent efforts toward creating a health contribution score (HCS) from the Godin Leisure-Time Exercise Questionnaire (GLTEQ) that reflects public-health guidelines for levels of moderate-to-vigorous physical activity (MVPA). The HCS yields categories of insufficiently active (less substantial or low benefits), moderately active (some benefits), and active (substantial benefits). The present study examined the validity of the GLTEQ HCS and its categories as reflecting levels of MVPA in multiple sclerosis (MS). Method: The sample included 684 persons with MS. Participants wore an accelerometer on an elastic belt around the waist above the nondominant hip during the waking hours of the day over a 7-day period and completed the GLTEQ. Results: The data analyses supported a large correlation between the GLTEQ HCS and accelerometer-measured MVPA, r = .46, p < .0001, but small correlations with accelerometer-measured light physical activity (LPA), r = .16, p < .001 and sedentary time, r = −.13, p = .001. There further was a large difference in accelerometer-measured MVPA between categories of physical activity levels (i.e., insufficiently active vs. active) based on the GLTEQ HCS (d = 0.89), but small differences in LPA (d = 0.39) and sedentary time (d = −0.31). Those results were unchanged in additional data analyses accounting for LPA and sedentary behavior. Conclusions: The GLTEQ HCS and categories primarily reflect MVPA rather than LPA and sedentary behavior in persons with MS.