Older adults face many age-related changes affecting functional ability. Function is defined as the interaction between a person and their real-world environment. Currently, no objective measures of function exist assessing the environmental component. A newly-developed measure of functional-living, the Movement and Activity in Physical Space (MAPS) score, combines accelerometer and geospatial data providing quantitative measurement of real-world function. Because MAPS is a new measure of functional-living, the purpose of the current study was to provide further construct validity for MAPS as a functional-living measure in older adults and to determine what combination of 3 days, using weekend and week days, are needed to obtain reliable MAPS scores in older adults. While there are many factors known to impact function, cognitive function has a well-known relationship with physical activity. MAPS assesses physical activity. Therefore, a relationship between cognitive function and functional-living was expected. Physical activity and physical function were also expected to be related to functional-living. Thirty community-dwelling older adults aged 72.6 (± 7.0) completed the study. Five measures of cognitive function were used, each assessing a different cognitive domain (i.e., executive function, working memory, processing speed, reaction time, and spatial visualization). A physical function test and a measure of physical activity were also administered. Pearson r correlations were conducted among all measures to assess the correlations between MAPS scores and the measures of cognitive function, physical activity questionnaire, and physical function test. If a correlation was found to be significant between MAPSI and MAPSV scores with any of the cognitive function measures, physical activity questionnaire, or physical function test, then further construct validity would be provided for MAPS as a functional-living measure in older adults. MAPSI and MAPSV scores were significantly correlated with the measure of processing speed and spatial visualization. The physical function score was also significantly correlated with MAPSI scores. The remaining measures of cognitive function and the physical activity questionnaire were not found to be associated with functional-living, as measured by MAPS, due to several limitations in the measures used. Wearing the activity monitors during any 3-day combination of days provided reliable MAPS data. Results of the study provided evidence of construct validity for MAPS as a functional-living measure.