This study evaluates the determinants of insurance coverage in the 18–24- year-old population using the National Medical Care Utilization and Expenditure Survey. Three specific issues are addressed: 1) the characteristics of the insured versus uninsured, 2) the reason given by the uninsured for not having coverage, and 3) the role of employment status and other variables in determining insurance status. An important consideration is whether age or usual activity is more important in its effect on insurance status. The results show that employment is the strongest predictor of insurance status in all age and usual activity subgroups. Generally, permanent/full-time workers are most likely to be insured. An exception to this trend is found for those attending school who are also permanent/part-time workers. These individuals are more likely to be insured than permanent full-time workers who are in school. Furthermore, young adults with lower incomes, less education, rural residence, not married, hispanic ethnicity, and Western geography are the least likely to be insured. The findings of this analysis can be used by policymakers to identify the mechanisms that can best enhance insurance coverage among young adults.