Medicaid Expansion In 2014 Did Not Increase Emergency Department Use But Did Change Insurance Payer Mix

Area of Science:

• Health Policy
• Health Services Research
• Public Health

Background:

• In 2014, the Patient Protection and Affordable Care Act enabled Medicaid expansion and Marketplace subsidies, leading to significant gains in health insurance coverage for millions of previously uninsured Americans.
• Policymakers anticipated that expanded Medicaid eligibility would substantially increase emergency department (ED) utilization.

Purpose of the Study:

• To investigate the impact of Medicaid expansion on ED utilization patterns during the first year of its implementation.
• To analyze shifts in ED visit payer mix and overall ED visit volume in response to insurance expansion.

Main Methods:

• Utilized difference-in-differences analysis comparing ED use in expansion states versus non-expansion states.
• Examined data from 478 hospitals across 36 states during the initial year of insurance expansion (2014).
• Assessed changes in ED visits categorized by payer (Medicaid, uninsured, privately insured) and total ED visits.

Main Results:

• Medicaid expansion led to a 27.1% increase in Medicaid-paid ED visits.
• Simultaneously, uninsured ED visits decreased by 31.4%, and privately insured visits declined by 6.7% in expansion states.
• Overall ED visit volume increased by less than 3% in 2014 compared to 2012-13, with no significant difference observed between expansion and non-expansion states.

Conclusions:

• Medicaid expansion significantly altered the payer mix of ED visits, shifting towards greater Medicaid utilization.
• Despite increased insurance coverage, overall ED visit volume did not significantly change, suggesting that expanded insurance did not substantially increase or decrease ED use.
• The findings indicate that insurance expansion primarily affected how ED services were paid for rather than the total number of visits.