The purpose of this longitudinal study was to closely examine the economic status of households that include individuals with intellectual disabilities in South Korea as well as the factors contributing to their poverty dynamics. The 2008 and 2012 panel data from the Korea Employment Agency for the Disabled were used to determine the income movement, poverty dynamics, and income patterns of families in the sustained nonpoverty and sustained poverty groups. Data from 87 households that include individuals with intellectual disabilities was used for analysis. Income mobility was assessed using a transition matrix between 2008 and 2012, and poverty and nonpoverty were determined based on the absolute poverty standard. Poverty dynamics were classified by the changes in poverty status in 2008 and 2012, including sustained poverty, sustained nonpoverty, poverty exit, and poverty entry. Income patterns were composed of earned income, social insurance, property income, and transfer income. The results showed that 66.7% of the households including individuals with intellectual disabilities showed no movement in income distribution and 82.8% of these families stayed in the lowest income distribution for both periods. The demographic characteristics of education level, multiple disabilities, and change in the number of employed members of the household were related to poverty dynamics. The ratio of earned income in the sustained nonpoverty group was significantly higher than that of the sustained poverty group, whereas the public transfer income ratio was significantly higher than in the sustained‐poverty group in 2008 and 2012. To reduce the prevalence and severity of poverty among households with individuals with intellectual disabilities, opportunities and quality of employment need to be secured, not only for individuals with intellectual disabilities, but also for their supporting family members.