ACA Coverage Cuts Young Adult ED Visits by 30%

Objectives: The Affordable Care Act (ACA), enacted in 2010, aimed to improve health insurance coverage and access to care, notably through a provision extending dependent coverage up to age 26 years. This study investigates the ACA’s impact on substance use disorder (SUD)–associated emergency department (ED) visits among young adults aged 23 to 29 years.

Study Design: A quasi-experimental study analyzed opioid- and alcohol-associated ED visits and inpatient admissions among young adults (aged 23-25 [treatment] vs 27-29 [comparison] years) using 2007-2019 Nationwide Emergency Department Sample data.

Methods: A difference-in-differences approach assessed the ACA’s impact, adjusting for covariates including sex, comorbidities, payer source, income, residence, and hospital region. Generalized linear models estimated adjusted ORs with 95% CIs, ensuring robust analysis of the ACA’s effects on substance-related health care utilization.

Results: Opioid-associated ED visits had no change between the treatment and comparison groups, whereas alcohol-associated ED visits declined more for the treatment group after the ACA (OR, 0.841; 95% CI, 0.828-0.855). No changes in inpatient admissions among opioid- or alcohol-associated visits, respectively, were seen between the 2 groups.

Conclusions: Our findings indicate that the ACA’s implementation led to mixed effects on substance-associated health care utilization among young adults, with reduced alcohol-associated visits in the treatment group but unchanged discrepancies in opioid-associated ED visits and inpatient admissions between the 2 groups. Further research is warranted to explore state-level variations and population-level substance use trends along with continuous monitoring to inform interventions addressing substance-associated public health challenges.

Am J Manag Care. 2025;31(9):In Press

This study examines how the Affordable Care Act (ACA) impacted substance-associated emergency department (ED) visits among young adults, highlighting its effects on health care utilization and policy implications.

Extending dependent insurance coverage under the ACA led to a decline in alcohol-associated ED visits, underscoring the importance of continuous insurance access.

No significant change in opioid-associated ED visits suggests a need for targeted interventions beyond insurance expansion.

Employers and policy makers should support comprehensive health benefits, including mental health and substance use treatment, to improve workforce well-being.

Ongoing evaluation of health care policies is crucial to addressing gaps in substance use disorder treatment.

The Affordable Care Act (ACA), which was enacted in 2010, was a transformative health policy initiative aimed at expanding health insurance coverage and improving access to care in the US, particularly for young adults. One of its key provisions allowed young adults to remain on their parents’ health insurance plans until age 26 years, addressing a critical gap in coverage for this demographic.1 Prior to the ACA, the uninsured rate was approximately 29% among individuals aged 18 to 24 years and approximately 27% among those aged 25 to 34 years.2 Lack of health care access can force young adults to rely on emergency departments (EDs) for their medical needs, including behavioral health issues such as substance use disorders (SUDs), due to limited access to primary and preventive health care services.3 The intention behind extending dependent coverage was to improve access to a range of health services, including outpatient treatment for SUDs, which have become increasingly prevalent among young adults.4

Over the past 2 decades, the rise in substance use and dependence has emerged as a pressing public health concern in the US, with SUDs affecting more than 20 million Americans annually.5,6 Younger adults aged 18 to 35 years are at heightened risk for risky substance use behaviors, including opioid use, excessive alcohol consumption, and recreational drug use.7 This age group is also significantly impacted by the ongoing opioid epidemic, resulting in a dramatic increase in opioid-related ED visits, which quadrupled between 1993 and 2010.8 The consequences of SUDs extend beyond individual health, including their contribution to increased morbidity and mortality rates exemplified by the 106,000 overdose deaths recorded in 2021 and the substantial economic burden on society.6,9

Young adults with SUDs frequently utilize ED services, often as a safety net because of the barriers to accessing ambulatory care. Research indicates that individuals with SUDs utilize ED services at rates 50% to 100% higher than those without such disorders.10 The proportion of ED visits associated with mental health and substance use has risen markedly, from 4% to 6% in the early 1990s to an estimated 12% by 2007.11 Between 2009 and 2017, the number of annual ED visits related to opioids and alcohol surged from 73,262 to 1,070,747, with a notable increase among young adults aged 21 to 29 years.12,13 Some of these visits may have been preventable, including through better access to outpatient care, but numerous barriers persist, including a shortage of providers who accept public insurance, stigma, and insufficient mental health and SUD resources.14,15 The ACA’s dependent coverage extension aimed to alleviate financial barriers, yet gaps in care for SUDs remain a challenge, as highlighted by literature examining the ACA’s effects on behavioral health and substance use outcomes.14

Despite the extension improving insurance coverage, the relationship between the ACA dependent coverage provision and ED utilization for SUDs is complex and multifaceted. Although the extension may enhance financial access to care, other structural and systemic barriers persist, particularly for populations with high unmet needs.16 Such challenges complicate the task of hypothesizing the ACA’s impact on ED visits a priori, as the effects of improved insurance coverage must be considered alongside the broader health care landscape.17

Sociodemographic disparities further complicate the landscape of ED visits for SUDs. Young adults in rural areas, those without insurance, and individuals from lower-income backgrounds are more likely to seek care in EDs for substance-related issues.18 Compared with their privately insured counterparts, Medicaid and uninsured patients tend to visit EDs more frequently for chronic conditions, mental health disorders, and SUDs.19 In 2017, more than 10.7 million ED visits were recorded for mental health or substance use issues, predominantly among middle-aged adults with low socioeconomic status.12,20,21 Although the ACA’s dependent coverage extension has been associated with improved access to care, the impact on substance use–related ED visits among young adults remains underexplored.

Study findings have shown that the ACA’s Medicaid expansion significantly reduced all-cause mortality, including deaths related to SUDs.22 However, research examining the effects of the dependent coverage provision on the highest-risk age group for SUDs (21-29 years) is limited. This gap in the literature raises questions about the complexities of access to care for young adults with SUDs, particularly in light of persistent barriers such as provider shortages and insurance limitations.14,15 Understanding how the ACA provision influences utilization of emergency services for young adult substance use is critical. Using the Nationwide Emergency Department Sample (NEDS), this study aimed to characterize the impact of the ACA dependent coverage extension on ED use among young adults (aged 23-29 years) for (1) alcohol use and (2) opioid use. Results of this analysis have important implications for health policy and practice.

Study Design and Data

NEDS, a deidentified data set, represents 20% of all US ED visits.23 NEDS data are collected annually; this analysis used the 2007, 2009, 2011, 2013, 2015, 2018, and 2019 data. This quasi-experimental study included an intervention group (aged 23-25 years) and a comparison group (aged 27-29 years). Those aged 26 years were excluded per prior research2 due to classification challenges. Opioid- and alcohol-associated ED visits were compared pre-ACA (2007-2009) and post ACA (2011-2019) because of their high prevalence and sensitivity to ACA-driven changes in access to care. Other substances were excluded due to lower prevalence and limited policy impact evidence. Of 19,856,756 total ED visits included in analyses, 164,929 were opioid associated and 285,578 were alcohol associated. The University of Nevada, Las Vegas Institutional Review Board deemed the study exempt due to the data set’s deidentified, public nature.

Four binary dependent variables investigated in this study were ED visits associated with use of opioids and alcohol, respectively, and admission to inpatient care after the opioid- or alcohol-associated ED visit.24 We utilized both principal and secondary diagnoses of opioid- and alcohol-associated ED visits in patients aged 23 to 25 years and 27 to 29 years using the International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification.25,26 Admission to inpatient care can indicate ED visits with relatively severe clinical conditions as opposed to ED visits that were unnecessary or for ambulatory care–sensitive conditions.27,28