The study reports on a set of questions added to the 1997-98 Annual Survey of Deaf and Hard of Hearing Children and Youth designed to take into consideration the functioning of children in their classroom in nine functional areas. Basing information on 30,198 students, the study describes prevalence rates of reported limitations in these functional areas for deaf and hard of hearing students, compares these to rates resulting from the reporting of categorically defined additional disabilities, and examines interrelationships among the items. Results of school estimates of students' functional hearing abilities are presented. The study's findings suggest a broader range and higher prevalence of functional limitations than would be assumed by analyzing categories of additional disabilities alone. The study's findings support the viability of functional assessment through large surveys. The discussion emphasizes the importance of functional assessment for the provision of appropriate educational services to deaf and hard of hearing children.