This article presents a profile of household-resident U.S. adults using wheeled mobility equipment (WME) in 2005, trends in WME use from 1990 to 2005, and data on accessibility features and problems from 1994-97. Data were obtained from the Survey of Income and Program Participation (SIPP) and the National Health Interview Survey on Disability (NHIS-D). Compared to the general population, WME users are more likely to be older, female, and in poor health. Forty-four percent are working-aged, with twice the rate of poverty of the general population, and only 17% are employed. Mobility difficulty is the most significant predictor of WME use, but gender, race, poverty, and educational attainment are also significant predictors. From 1990-2005, WME use grew 5% per year, while mobility difficulty declined among the elderly and remained steady among working-age persons. This contrast suggests a reduction in unmet need for WME. In 1994-97, more than half of WME users had difficulty entering or exiting their homes, and one-third had accessibility problems outside their homes. Usage of home modification was low, with substantial unmet need. Regular national data collection on the use of WME and other mobility aids, their financing, and accessibility issues is warranted. (Contains 4 tables and 5 figures.)