Medi-Cal Enrollment Declines Amid Heightened Immigration Enforcement in California
Introduction
Medi-Cal, California’s Medicaid program, provides health coverage to millions of low-income Californians and plays a critical role in improving access to care, reducing financial barriers to treatment, and promoting population health.1 In recent years, California expanded full-scope Medi-Cal eligibility to include income-eligible undocumented adults, making the state a national leader in providing health coverage regardless of immigration status.2 Expansions to young and older adults were intended to reduce longstanding disparities in health insurance coverage and improve access to care among immigrant communities.
Research has shown that immigration enforcement and anti-immigrant policy environments can affect participation in public programs, even when eligibility rules remain unchanged. Individuals and families may avoid interacting with government agencies or public institutions due to fear of potential immigration consequences. This phenomenon, commonly referred to as a “chilling effect,” occurs when eligible individuals choose not to enroll in or maintain participation in public programs despite remaining eligible for benefits.3 Recent studies indicate that immigrants are reluctant to access health care out of concern that providers will share information about their immigration status with immigration enforcement authorities.4 In California, prior research has found evidence that some Latino and Asian immigrants may avoid Medi-Cal enrollment because of concerns about immigrant status and public benefit use, even after changes to the federal public charge rule were reversed.5
These concerns may extend beyond undocumented immigrants themselves. Approximately 70% of undocumented immigrants live in mixed-status households that include U.S.-citizen or lawfully present family members. As a result, immigration enforcement activity may influence enrollment and participation decisions among individuals who remain eligible for public programs, including citizen children and documented members of mixed-status families.6
Beginning in late spring and continuing through the end of 2025, immigration enforcement activity increased substantially across California. According to tabulations of Deportation Data Project records, more than 3,200 individuals were arrested each month statewide from June through December 2025, more than three times the monthly average from January through May 2025.7 More than half of those arrested during this period had no history of criminal convictions, and the vast majority were adults.
During this period, enforcement activities conducted by Immigration and Customs Enforcement (ICE) and U.S. Border Patrol received widespread attention and generated concern among immigrant communities.8 Community organizations, health providers, and advocates also reported growing fears among immigrant residents about engaging with public institutions and accessing public services.
While other researchers have documented recent Medicaid enrollment declines,9 less attention has been given to whether heightened enforcement activity may have contributed to enrollment changes among populations most likely to be affected by immigration enforcement concerns.
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.
Data and Approach
This analysis draws on three data sources: Medi-Cal enrollment data, Expansion Medi-Cal enrollment data, and arrest records from the Deportation Data Project. The first two datasets are provided by the California Department of Health Care Services (DHCS) and contain aggregated counts of enrollment by county and demographic characteristics.10 The Expansion Medi-Cal population consists primarily of undocumented adults eligible for full-scope Medi-Cal in California in 2025, along with a smaller number of other eligible groups. 11 Some information is suppressed for confidentiality, particularly for smaller counties and smaller demographic groups.
The Expansion Medi-Cal dataset includes only adults aged 19 and older. Data on race and ethnicity are available only for individuals ages 26 to 49.12 To provide context on immigration enforcement activity, we use arrest records from the Deportation Data Project, a research initiative operated by UC Berkeley and UCLA.13 The dataset contains individual arrest records without personal identifiers to protect confidentiality. For this analysis, we use arrest records occurring within California’s three ICE administrative areas of responsibility and exclude arrests occurring outside the state.
We 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. We 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.
This analysis is descriptive and does not necessarily establish a causal relationship between immigration enforcement and Medi-Cal enrollment declines. The comparison between expansion and non-expansion enrollment provides useful context, but the non-expansion population is not a perfect counterfactual because the two groups may differ in renewal timing, eligibility stability, income volatility, and responsiveness to administrative processes. We reviewed available information on policy and administrative changes during the study period and did not identify major changes specific to the Medi-Cal expansion population that would explain the divergence in trends.14 However, other explanations cannot be ruled out. Seasonal enrollment patterns may have contributed to declines in the second half of the year, particularly because non-expansion enrollment also declined. In addition, rising wages may have pushed some potential enrollees above income eligibility thresholds. Finally, although state policy news alone is unlikely to explain the full decline, the Governor’s May 2025 proposal to freeze Medi-Cal coverage for undocumented adults may have discouraged some eligible individuals from enrolling or renewing coverage. For these reasons, the findings should be interpreted as enrollment patterns consistent with a chilling effect, rather than definitive evidence of one.
Key Findings
Finding 1: Adult Medi-Cal expansion enrollment reversed course after mid-2025.
At the start of 2025, approximately 1.42 million adult Californians were enrolled in the Medi-Cal expansion population. Enrollment increased modestly during the first half of the year, reaching nearly 1.45 million enrollees by mid-2025. Enrollment remained relatively stable through July before beginning a steady decline during the second half of the year.
By December 2025, adult expansion enrollment had fallen to approximately 1.38 million enrollees, a decline of nearly 71,000 individuals from its June level. As shown in Figure 1, enrollment increased during the first half of the year, then reversed course after mid-year and declined through the remainder of 2025.
The timing of this reversal coincided with a period of heightened immigration enforcement activity in California. This pattern is consistent with concerns that immigration enforcement may have discouraged some eligible individuals from enrolling in or maintaining Medi-Cal coverage.
Figure 1. Indexed Enrollment Trends for Adult Medi-Cal Expansion and Non-Expansion Populations, 2025
Note: Enrollment is indexed to June 2025 (June = 100), indicated by the vertical dashed line. June 2025 corresponds to the period immediately preceding the increase in immigration enforcement activity examined in this brief. Values above 100 indicate enrollment levels higher than June 2025, while values below 100 indicate lower enrollment levels.
Source: Authors’ calculations of California Department of Health Care Services, Monthly Eligibility Data, 2025.
Finding 2: Enrollment declines were more than twice as large among expansion enrollees as among non-expansion enrollees.
Figure 2 highlights how enrollment patterns among the adult Medi-Cal expansion and non-expansion populations diverged over the course of the year. During the first half of 2025, enrollment in the expansion population increased by approximately 1.9%, while enrollment in the non-expansion population declined by 1.3%. During the second half of the year, enrollment declined in both groups, but the decline in expansion enrollment was more than twice as large as the decline among non-expansion enrollees (4.8% vs. 2.3%).
While other factors may have influenced enrollment patterns, the substantially larger decline among expansion enrollees is consistent with concerns that heightened immigration enforcement activity may have discouraged some eligible individuals from enrolling in or maintaining Medi-Cal coverage.
Figure 2. Percentage Change in Adult Medi-Cal Expansion and Non-Expansion Enrollment During 2025
Note: The figure shows the percent change in enrollment during the first half (January–June) and the second half (July–December) of 2025.
Source: Authors’ calculations of California Department of Health Care Services, Monthly Eligibility Data, 2025.
Finding 3: Both Latino and non-Latino expansion enrollees experienced enrollment declines after mid-2025.
As shown in Figure 3, enrollment trends for Latino and non-Latino expansion enrollees followed similar trajectories throughout 2025. Both groups experienced modest enrollment growth during the first half of the year, followed by sustained declines after June. Between July and December 2025, enrollment declined by approximately 5.5% among Latino enrollees and 6.0% among non-Latino enrollees.
The similarity of these trends suggests that the decline in enrollment among the expansion population was not concentrated within a single ethnic group. Rather, enrollment decreases were observed across multiple demographic groups within the expansion population.
Figure 3. Indexed Expansion Enrollment Trends by Ethnicity, Ages 26–49, 2025
Note: Enrollment is indexed to June 2025 (June = 100), indicated by the vertical dashed line. June 2025 corresponds to the period immediately preceding the increase in immigration enforcement activity examined in this brief.
Source: Authors’ calculations of California Department of Health Care Services, Monthly Eligibility Data, Medi-Cal Adult Full Scope Expansion Programs, 2025.
Finding 4: Enrollment patterns among the expansion population suggest a potential chilling effect beyond the direct effects of ICE arrests.
Figure 4 shows monthly ICE arrests among adults aged 19 and older in California during 2025. Arrest activity increased sharply beginning in June 2025 and remained elevated throughout the second half of the year. Between July and December 2025, approximately 18,400 adults were arrested across California. The timing of this increase coincided with the period when Medi-Cal expansion enrollment stopped increasing and began to decline.
Figure 4. Monthly ICE Arrests in California Among Adults Ages 19 and Older, 2025
Source: Authors’ calculations of Deportation Data Project arrest records, 2025.
To better understand the relationship between increased immigration enforcement activity and declining enrollment, we decomposed the observed decline in Medi-Cal expansion enrollment into three components: expected enrollment declines based on broader Medi-Cal trends, the direct effects of ICE arrests, and a component that may reflect a chilling effect. Figure 5 presents the results from this analysis.
Nearly half (48%) of the total decline in expansion enrollment between July and December 2025 is explained by broader Medi-Cal trends. During this time period, enrollment declined by approximately 70,000 individuals. If enrollment in the expansion population had followed the same pattern as the non-expansion population, we estimate that enrollment would have declined by approximately 33,400 individuals, leaving an excess decline of 36,600 individuals.
We then estimated the potential direct effect of ICE arrests using arrest records from the Deportation Data Project. Restricting the analysis to individuals potentially eligible for Medi-Cal, we estimate that approximately 13,700 individuals of the excess decline could be associated with direct ICE enforcement activity, explaining 20% of the total decline between July and December.15 Because not all eligible individuals were enrolled in Medi-Cal, this likely represents an upper-bound estimate of the direct effects of ICE arrests.16
After accounting for broader enrollment trends and the estimated direct effects of ICE arrests, approximately 22,900 enrollment losses remain unexplained (33% of the decline). We interpret this decline as being consistent with a potential chilling effect, in which eligible individuals avoid enrolling in or maintaining participation in public programs because of fear, uncertainty, or perceived risks associated with government engagement.17
Figure 5. Estimated Components of the Medi-Cal Expansion Enrollment Decline, July–December 2025
Note: Between July and December 2025, enrollment declined by approximately 70,000 individuals. The figure decomposes the observed decline in expansion enrollment into three components: expected declines based on broader Medi-Cal enrollment trends, estimated direct effects of ICE arrests, and a residual component. We interpret this residual component as being consistent with a potential chilling effect.
Source: Authors’ calculations of California Department of Health Care Services, Monthly Eligibility Data, 2025; Deportation Data Project.
Conclusion and Implications
The findings presented in this brief are consistent with a chilling effect associated with heightened immigration enforcement activity in California during 2025. Expansion enrollment reversed course after mid-year, declined more rapidly than non-expansion enrollment, and experienced enrollment losses greater than expected based on broader Medi-Cal trends alone. While these findings do not establish a direct causal relationship, they suggest that concerns about immigration enforcement may have influenced enrollment decisions among populations eligible for Medi-Cal expansion.
Implication 1 – Immigration Fears Disrupt Health Care Access: Evidence from other states suggests that immigration enforcement activity may affect health care utilization and health insurance enrollment. Following increased immigration enforcement activity, health care organizations reportedly experienced appointment cancellation rates as high as 50% and a substantial increase in requests for in-home services.18 These concerns may be further amplified by current efforts to revise the “public charge” rule, since recent research suggests that uncertainty around public charge policy can itself discourage benefit use, and research shows that mis- and disinformation about public charge already deters some Latino immigrants from seeking care or enrolling in public programs such as Medicaid.19
Implication 2 – Immigration Enforcement Contributes to Stress, and Forgone Care: National survey data indicate that these concerns may be widespread. Approximately one-third of immigrant respondents reported negative health impacts related to immigration-related stress, including increased anxiety, stress, and difficulties with eating or sleeping.20 In a separate survey, 13% of likely undocumented immigrants reported avoiding routine activities, including seeking medical care, because of concerns about immigration enforcement.21
Implication 3 – Chilling Effects Spill Over to Children’s Health: These effects may extend beyond undocumented adults themselves. Approximately 12% of children in the U.S. has at least one noncitizen immigrant parent,22 and concerns about immigration enforcement may also affect U.S.-citizen children living in mixed-status families. Compared to families with two U.S. citizen parents in California, families with one or both noncitizen parents were more likely (by 38 and 47 percentage points, respectively) to avoid applying for benefits because of immigration-related concerns.23 Such disruptions in care can contribute to missed vaccinations, worsening chronic and mental health conditions, and the progression of otherwise preventable illnesses.
Implication 4 – Coverage Losses Could Deepen Health Inequities: Taken together, these findings suggest that the current immigration and policy environment has implications that extend beyond immigration outcomes alone. Reduced engagement with health care systems and public benefit programs among eligible populations could have lasting consequences for population health, health equity, and access to preventive care. Additional eligibility and enrollment restrictions could further reduce Medi-Cal coverage among undocumented immigrants and their families,24 potentially exacerbating existing disparities in access to health coverage and care.25
End Notes
1 California Department of Health Care Services (DHCS), Medi-Cal Monthly Eligible Fast Facts: May 2026 (Date Represented: February 2026), June 2026, accessed June 9, 2026, available online.
2 California Department of Health Care Services (DHCS), “Ages 26 through 49 Adult Full Scope Medi-Cal Expansion,” December 14, 2023, accessed June 9, 2026, available online.
3 “Tara Watson, “Inside the Refrigerator: Immigration Enforcement and Chilling Effects in Medicaid Participation,” American Economic Journal: Economic Policy 6, no. 3 (2014): 313–38, available online.
4 Drishti Pillai et al., “KFF/New York Times 2025 Survey of Immigrants: Health and Health Care Experiences During the Second Trump Administration,” KFF, November 18, 2025, available online.
5 Arturo Vargas Bustamante, Lucía Félix-Beltrán, Joseph Nwadiuko, and Alexander N. Ortega, “Avoiding Medicaid Enrollment After the Reversal of the Changes in the Public Charge Rule Among Latino and Asian Immigrants,” Health Services Research 57, Suppl. 2 (2022): 195–203, available online.
6 National Immigration Forum, Fact Sheet: Mixed Status Families and COVID-19 Economic Relief, August 12, 2020, available online.
7 Authors’ tabulations of Deportation Data Project arrest records for California’s three ICE Areas of Responsibility, July–December 2025.
8 John Raphling and Brian Root, US: ICE Abuses in Los Angeles Set Stage for Other Cities, Human Rights Watch, November 4, 2025, available online.
9 Other studies have examined the decline of Medicaid enrollment in 2025, but are not focused on assessing the impact of ICE enforcement on this decline. See, for example, Georgetown University McCourt School of Public Policy, Center for Children and Families, “State by State Medicaid and CHIP Enrollment Data,” accessed Jun 5, 2026, available online.
10 DHCS frequently uses the term “eligible” to refer to individuals included in program counts. Throughout this brief, we use the terms “enrollees” and “enrolled” to refer to those counts.
11 According to DHCS (via email correspondence with the DHCS Open Data Team, June 2026), the Adult Expansion dataset includes individuals without immigration status as well as some lawfully present adults who are not eligible for federally funded Medicaid benefits. The dataset does not identify specific immigration status and therefore cannot distinguish undocumented enrollees from other newly eligible groups. However, other researchers have used expansion enrollment as a proxy for undocumented immigrants on Medi-Cal. See, for example: Leonard, Russell, and Brandy J. Lipton. “The California 2020 Medi-Cal Expansion to Young Adults and Coverage Among Noncitizens.” JAMA Network Open 9, no. 5 (2026): e2612332; Laurel Lucia, Miranda Dietz, and Alexis Manzanilla, The Importance of Comprehensive Health Benefits for All Low-Income Californians, UC Berkeley Labor Center, May 2025; and Jenny S. Guadamuz, Stacy Chen, and Arturo Vargas Bustamante, “Medicaid Expansion for Undocumented Adults and Its Association with Health Insurance Coverage Among Noncitizens in California, 2017–2023,” Health Affairs Scholar 4(1) (2026), available online.
Moreover, we find similar results when examining Los Angeles County enrollment trends using administrative data from the Los Angeles County Department of Public Social Services, which reports Medi-Cal enrollment counts for undocumented residents. See Los Angeles County Department of Public Social Services, Statistical Reports, accessed June 9, 2026, available online.
12 California Department of Health Care Services, “Medi-Cal Adult Full Scope Expansion Programs,” June 2, 2026, Monthly Eligibility, available online.
13 Deportation Data Project, UC Berkeley and UCLA, accessed June 8, 2026, available online.
14 HCS, Tracking Federal Impact: Medi-Cal Eligibility, Department of Healthcare Services, n.d., accessed June 3, 2026, available online.
15 We exclude those detained after release from a jail or prison. These individuals would not have been eligible for Medi-Cal while incarcerated. We also exclude those arrested while trying to enter the border or arrested by those responsible for border control. We did not exclude ex-convicts arrested in the community at large because they could have become Medi-Cal eligible after their release. These estimates assume that changes in enrollment occur contemporaneously with immigration enforcement activity. Applying a one-month lag between arrests and enrollment changes yields similar results because arrest levels remained elevated throughout the second half of 2025.
16 Using this figure would likely overestimate ICE arrestees who did enroll because it is unlikely that all of these undocumented were enrolled in the program; consequently we underestimate the number who left Medi-Cal without being arrested by ICE.
17 We observe similar patterns among Latino expansion enrollees ages 26 to 49. In this subgroup, the majority of the estimated excess decline is also attributable to the residual component consistent with a potential chilling effect.
18Munira Maalimisaq, “Fear of Immigration Enforcement Is Driving a Public Health Crisis in Minnesota,” BMJ 392 (February 2026): s366, available online.
19Arturo Vargas Bustamante, Clara B. Barajas, and Alexander N. Ortega, “The Public Health Consequences of the 2025 Public Charge Announcements—Uncertainty as Policy,” JAMA Network Open 9, no. 1 (2026): e2555044, available online; Clara B. Barajas et al., “Organizational Perspectives on the Public Charge Rule and Health Care Access for Latino Immigrants in California,” Health Services Research 61, no. 2 (2026): e70032, available online.
20 Shannon Schumacher, “KFF Survey of Immigrants: Views and Experiences in the Early Days of President Trump’s Second Term,” KFF, May 8, available online.
21 Ibid.
22 Drishti Pillai, Akash Pillai, and Samantha Artiga, Children in Immigrant Families: Key Facts on Health Coverage and Care, KFF, May 19, 2026, available online.
23 Clara B. Barajas et al., “Public Benefit Avoidance and Safety Concerns Among Mixed-Status Latino Families in California, 2021–22,” Health Affairs 44, no. 10 (2025): 1307–1316, available online.
24 Miranda Dietz, Srikanth Kadiyala, Annie Rak, Sun-Yin Ho, Dylan H. Roby and Laurel Lucia, “Projected reduction in Medi-Cal coverage due to federal H.R.1 and 2025-26 State Budget, by county, 2028,” February 18, 2026, UC Berkeley Labor Center, accessed Jun 5, 2026, available online.
25 Arturo Vargas Bustamante, Marvin Chowdhury, and Alexander N. Ortega, “Expanding Medicaid for Undocumented Immigrants: A Path to Better Coverage and Population Health,” American Journal of Public Health 115, no. 6 (2025): 830–832, available online. Arturo Vargas Bustamante et al., “Shifting Federal and State Policy Landscapes for Health Insurance Coverage of Noncitizen Immigrants: Where Are We 30 Years After PRWORA?,” Journal of Health Politics, Policy and Law 50, no. 6 (2025): 945–970, available online.
Acknowledgments
This brief was made possible in part by the generous support of the James Irvine Foundation. The authors thank Jonathan Ong for his assistance in developing the data management and analytical programs used in the ICE arrest analysis, and Cristian Rivera for his assistance with dissemination and media outreach.
The UCLA Latino Policy and Politics Institute and the UCLA Center for Neighborhood Knowledge acknowledge the Gabrielino and Tongva peoples as the traditional land caretakers of Tovaangar (the Los Angeles basin and Southern Channel Islands) and that their displacement has enabled UCLA’s flourishing. As a land grant institution, we pay our respects to the Honuukvetam (Ancestors), Ahiihirom (Elders), and Eyoohiinken (our relatives nations) past, present, and emerging.
Disclaimer
The views expressed herein are those of the authors and not necessarily those of the University of California, Los Angeles as a whole. The authors alone are responsible for the content of this report.
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