Control of communicable diseases in children, including respiratory and diarrheal illnesses that affect U.S. school-aged children, might require public health preventive efforts both in the home and at school, a primary setting for transmission. National Health Interview Survey (NHIS) data on school absenteeism and gastrointestinal illness in the United States during 2010-2016 were analyzed to identify associations among income, illness, and absenteeism. Prevalence of gastrointestinal and respiratory illnesses in the 2 weeks preceding the survey increased as income decreased. Although the likelihood of missing any school days during the past year decreased with reduced income, among children missing school, those from low-income households missed more days of school than did children from higher income households. Although the reason for absenteeism cannot be ascertained from this analysis, these data underscore the importance of preventive measures, such as hand hygiene promotion and education, and the opportunity for both homes and schools to serve as an important point for implementation of public health preventive measures, including hand hygiene practice and education.