More adults than children with congenital heart disease (CHD) are alive today. Few studies have evaluated adult congenital heart disease (ACHD) health care utilization in the United States. Data from the National Inpatient Sample from 2002 to 2012, using International Classification of Diseases, Ninth Revision, codes for moderate and complex CHD were analyzed. Hospital discharges, total billed and reimbursed amounts, length of stay, and gender/age disparities were evaluated. There was an increase in CHD discharges (moderate CHD: 4,742 vs 6,545; severe CHD: 807 vs 1,115) and total billed and reimbursed dollar amounts across all CHD (billed: $2.7 vs $7.0 billion, 155% increase; reimbursed: $1.3 vs $2.3 billion, 99% increase) and in the ACHD subgroup (billed: $543 million vs $1.5 billion, 178% increase; reimbursed: $221 vs $433 million, 95% increase). Women comprised more discharges in 2002 but not in 2012 (men:women, 2002: 6,503 vs 7,805; 2012: 7,715 vs 7,200, p = 0.39). Gender-based billed amounts followed similar trends (2002: $263 vs $280 million; 2012: $845 vs $662 million, p = 0.006) as did reimbursements (2002: $108 vs $114 million; 2012: $243 vs $190 million, p = 0.008). All age subgroups demonstrated increased health care expenditures, including the >44 versus 18- to 44-year-old age subgroup (billed: $618 vs $347 million, p <0.001; reimbursed: $136 vs $75 million, p <0.001). Our results reveal increased ACHD billed and reimbursed amounts and hospital discharges with a shift in gender-based ACHD hospitalizations: men now account for more hospitalizations in the United States. In conclusion, increased health care expenditure in older patients with ACHD is likely to increase further as health care system use and costs continue to grow.