BACKGROUND AND OBJECTIVES: Fifteen percent of US children live in households with inadequate food. Children who are food insecure often experience worse physical, emotional, and developmental health outcomes. Authors of previous studies have not examined the quality and cost implications of food insecurity in children. METHODS: This is a retrospective study of 7959 nationally representative US children (aged 1-17 years) in the 2016 Medical Expenditure Panel Survey. Households with food insecurity were identified by $3 positive responses to the 30-day, 10-item US Food Security Survey. Main outcomes were annual health expenditures and quality of care indicators: emergency department (ED) and inpatient use, primary care and specialist visits, routine medical and dental care, patient experience measures, and school absenteeism. Logistic and 2-part regression models were constructed to estimate outcomes conditional on sociodemographic and medical covariates. RESULTS: Children in households with food insecurity were more often publicly insured and had special needs compared with all other children. In multivariable logistic regression, household food insecurity was associated with significantly higher adjusted odds of an ED (adjusted odds ratio [aOR] = 1.37) or primary care treatment visit (aOR = 1.24) during the year. Household food insecurity was associated with significantly higher school absenteeism (aOR = 1.74) and lower access to care for routine (aOR = 0.55) or illness (aOR = 0.57) care. There were no differences in annual health expenditures, hospitalizations, or receipt of routine medical or dental care. CONCLUSIONS: Household food insecurity is associated with higher ED use and school absenteeism and lower access to care; however, it was not associated with higher annual health expenditures in children. WHAT'S KNOWN ON THIS SUBJECT: Fifteen percent of US children experience food insecurity. Children who are food insecure are less likely to attain healthy growth and development. The relationship between food insecurity, health care service use, quality of care, and expenditures is not well established in children. WHAT THIS STUDY ADDS: Using national US survey data, we found that household food insecurity was associated with higher emergency department use and school absenteeism and lower access to care quality among children; however, there were no differences in annual health expenditures.