Transportation mobility is critically important to the well-being of the elderly population. By using data from the 2009 National Household Travel Survey, this paper proposes a metric to measure immobility among elderly over different time frames. Specifically, “short-term immobility” is defined as immobility for a single day while “long-term immobility” refers to immobility of a week or more, and “medium-term immobility” is between 2 to 7 days. In addition, long-term immobile elderly are divided into two mobility-preference groups on the basis of whether they prefer going out of their home. With this immobility metric, and respondent-stated mobility preferences, descriptive analysis and discrete choice models are used to analyze the correlates of immobility among the American elderly. African American elderly are found to be more likely to be long-term immobile than those from other racial groups. Such racial differences are not readily apparent in immobility over shorter time frames. This result explains that most previous studies did not find any racial differences in elderly mobility because of the shorter time frames of analysis of those studies. The presence of another elderly companion in the household is found to have a significant positive influence on a person's mobility. Medical conditions may impose physical constraints on the ability to travel but do not seem to curb the desire for mobility among the elderly. However, the inability to drive is associated with a strong preference against going out of the home, suggesting that the automobile-centric land-use transportation system can potentially curb the desire of nondriving elderly to travel out of the home.