This brief examines whether Medi-Cal enrollment patterns during 2025 are consistent with a chilling effect associated with heightened immigration enforcement activity. The findings are descriptive and should not be interpreted as establishing a causal relationship. However, they provide evidence of enrollment patterns that are consistent with broader concerns about immigration enforcement and access to health coverage. Authors compared monthly enrollment trends in California’s Medi-Cal expansion and non-expansion populations throughout 2025, focusing on the second half of the year when immigration enforcement activity became more intense, visible, and widely publicized. They then examined enrollment changes by race and ethnicity and compared observed enrollment declines with ICE arrest activity to assess whether enrollment patterns were consistent with a potential chilling effect associated with heightened immigration enforcement activity.

Findings: 

• Adult Medi-Cal expansion enrollment reversed course after mid-2025, declining by nearly 71,000 individuals from June to December 2025. 
• Enrollment declines were more than twice as large among adult Medi-Cal expansion enrollees (4.8%) as among non-expansion enrollees (2.3%) during the second half of 2025. 
• Both Latino (5.5%) and non-Latino (6%) expansion enrollees experienced enrollment declines after mid-2025. 
• Enrollment patterns among the expansion population suggest a potential chilling effect beyond the direct effects of ICE arrests.

Authors conclude that the findings are consistent with a chilling effect associated with heightened immigration enforcement activity in California during 2025.

This article features Arturo Vargas Bustamante, senior fellow at the UCLA Center for Health Policy Research.