A full conceptualization of the elderly food insecurity experience has been lacking, leading to limitations in the definition and measurement of food insecurity in elders. Based on the qualitative analysis of two in-depth interviews 6 mo apart with each of 53 low income urban elders, using principles of grounded theory, the experience of elderly food insecurity was shown to have four components: quantitative, qualitative, psychological and social. The inability to obtain the right foods for health is a new element specific to elders. Common to each of these components were dimensions of severity, time and compromised food choice. Although money is a major cause of food insecurity, elders sometimes have enough money for food but are not able to access food because of transportation or functional limitations, or are not able to use food (i.e., not able to prepare or eat available food) because of functional impairments and health problems. These findings suggest that augmentation of the U.S. Household Food Security Survey Module (FSSM), a national measure of food insecurity based on research in younger persons, may result in more accurate assessments for elders. We developed 14 new items for possible augmentation and administered them by telephone to these same elders along with the FSSM. Elders were independently classified according to food insecurity status based on their experience from the in-depth interviews, and these definitive criteria were used to evaluate the new and existing items. The results suggest that "couldn't afford right foods for health" and two policy-relevant immediate causes, "couldn't get the food I needed" and possibly "unable to prepare," should be added, although further testing is needed.