TOPLINE:

Emergency department (ED) visits in California increased by 38%, rising from 10.8 in 2008 to 14.8 million in 2023. Visits by Medicaid patients increased the most — by 33.3%. Outpatient visits increased across all payer groups, whereas admission rates declined; the decrease was especially pronounced among uninsured patients, who experienced a 45% drop.

METHODOLOGY:

• Researchers analyzed all ED visits from licensed general acute care hospitals in California using data from the California Department of Healthcare Access and Information, the State Health Access Data Assistance Center, and the US Census between 2008 and 2023.
• ED visits were categorized as either discharged (outpatient visits) or admitted (inpatient visits), and payers were grouped into Medicare, Medicaid, private insurance, uninsured, or other/unknown categories.
• The study outcome was trends in ED visits between 2008 and 2023, with researchers comparing discharged and admitted visits across payer groups.

TAKEAWAY:

• Between 2008 and 2023, annual ED visits increased by 38%, from 10.8 million to 14.8 million visits. Population-adjusted rates rose by 29%, from 294 to 380 visits per 1000 enrollees.
• Medicaid beneficiaries experienced the largest increase in visit rates (33.3%; P < .001), significantly higher than the 12.5% growth among Medicare beneficiaries. Visit rates among privately insured and uninsured individuals rose modestly — by 5.2% and 2.2%, respectively.
• Discharge visit rates per 1000 enrollees increased substantially for Medicaid patients (37.6%, from 507.2 to 698.0) and Medicare patients (27.7%, from 302.4 to 386.1), with modest increases for privately insured (8.0%) and uninsured (6.7%) individuals.
• Admission rates decreased across most payer groups, with the steepest decline among uninsured patients (45%), followed by privately insured patients (16.5%), Medicare patients (12.8%), and Medicaid patients (3.3%).

IN PRACTICE:

"As the ED increasingly functions as a site for unscheduled or after-hours care, policy responses focused solely on coverage may overlook operational and access drivers," the authors wrote.

SOURCE:

The study was led by Maya Spencer, BA, University of California, San Francisco. It was published online as a research letter on December 26, 2025, in JAMA Health Forum.

LIMITATIONS:

The study's findings were limited by the focus on California data without geographic stratification and by the absence of observation capture capabilities. The aggregated insurance categories did not fully reflect the complexity of coverage types, including dual eligibility and Medicare Advantage variations. Additionally, the other/unknown insurance category included a diverse group of patients, such as those with limited-benefit plans and military/Veterans Affairs coverage, which may have masked specific utilization patterns.

DISCLOSURES:

The study did not provide any funding information. The authors declared no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.