OBJECTIVE: To examine the effect of the transition to adulthood on financial and non-financial barriers to care in youth with asthma. STUDY DESIGN: With National Health Interview Survey data from 2000 to 2005, we examined delays and unmet needs because of financial and non-financial barriers, evaluating the effect of adolescent (age, 12-17 years; n = 1539) versus young adult age (age, 18-24 years; N = 833), controlling for insurance, usual source of care, and sociodemographic characteristics. We also simulated the effects of providing public insurance to uninsured patients and a usual source of care to patients without one. RESULTS: More young adults than adolescents encountered financial barriers resulting in delays (18.6% versus 8%, P < .05) and unmet needs (26.6% versus 11.4%, P < .05), although delays caused by non-financial barriers were similar (17.3% versus 14.9%, P = not significant). In logistic models young adults were more likely than adolescents to report delays (odds ratio [OR], 1.45; 95% CI, 1.02-2.08) and unmet needs (OR, 1.8; 95% CI, 1.29-2.52) caused by financial barriers. CONCLUSIONS: Delays and unmet needs for care caused by financial reasons are significantly higher for young adults than they are for adolescents with asthma.