Highlights
- In May 2022, California’s expansion of full-scope Medi-Cal to undocumented immigrants aged 50 and older catalyzed a significant increase in the prescription of Guideline-Directed Medical Therapy (GDMT).
- The use of SGLT-2 inhibitors among older undocumented immigrants tripled (6.5% to 21%), while GLP-1 receptor agonist prescriptions increased 13-fold (1.1% to 14%) post-expansion.
- The gap in prescription rates between documented and older undocumented patients narrowed to within 1.5–4.6 percentage points by the end of the study period.
- The rate of increase in the odds of receiving newer T2D medications was 6% higher per month for newly eligible undocumented patients compared to documented patients, demonstrating a rapid catch-up effect.
Background
Type 2 diabetes (T2D) remains a disproportionate burden for Hispanic/Latino populations in the United States, often compounded by systemic barriers to healthcare access, particularly for undocumented immigrants. For decades, the therapeutic landscape of T2D was dominated by metformin and insulin. However, the last decade has seen a paradigm shift with the emergence of sodium-glucose cotransporter 2 inhibitors (SGLT-2i) and glucagon-like peptide 1 receptor agonists (GLP-1 RA). These classes have moved beyond simple glycemic control to offer profound cardiorenal protection, as evidenced by pivotal trials such as EMPA-REG OUTCOME and LEADER. Despite their inclusion in the American Diabetes Association (ADA) Standards of Care as preferred treatments for high-risk patients, their high cost often renders them inaccessible to those without comprehensive insurance.
In California, the 2022 expansion of Medi-Cal to low-income undocumented immigrants aged 50 or older represented a landmark policy aimed at addressing these disparities. Prior to this, undocumented individuals often relied on restricted-scope Medicaid (emergency-only) or safety-net programs that did not cover the high costs of newer, branded medications. This review synthesizes recent real-world evidence on how this policy change influenced prescribing behaviors in primary care settings, specifically looking at the transition from traditional therapies to modern GDMT.
Key Content
1. Methodological Approach and Population Dynamics
Recent research by Ro et al. (2026) utilized a robust longitudinal design, analyzing records from two major Federally Qualified Health Centers (FQHCs) in Los Angeles County from January 2019 to June 2023. The study cohort (n = 4,601 patients) was predominantly Hispanic/Latino (86% in the undocumented group), reflecting the demographic most impacted by the policy change. By employing Generalized Linear Mixed Models (GLMMs) with patient-level random intercepts, the researchers were able to account for individual variability while measuring the population-level impact of the policy expansion.
The study compared three distinct cohorts: 1) older undocumented immigrants (newly eligible), 2) younger undocumented immigrants (remaining ineligible), and 3) documented patients. This design allowed for a quasi-experimental assessment of the policy’s effect, separating time-based trends in diabetes care from the specific impact of gaining insurance coverage.
2. Comparative Analysis of Prescribing Patterns
Before the May 2022 expansion, a stark disparity existed. Older undocumented patients were largely restricted to older, generic medications. Metformin and long-acting insulin were the staples of therapy. While these are effective for glucose lowering, they do not provide the weight loss and organ-protective benefits associated with SGLT-2i and GLP-1 RA. In the pre-expansion phase, SGLT-2i use was only 6.5% and GLP-1 RA use was a mere 1.1% in the older undocumented group.
Post-expansion, the shift was dramatic. For older undocumented immigrants, SGLT-2i prescriptions rose to 21% and GLP-1 RA rose to 14%. While a general upward trend was noted across all groups—reflecting a broader clinical shift toward newer therapies—the rate of increase in the newly eligible group was significantly steeper. The adjusted odds ratio (aOR) for the interaction between time and patient group showed that the odds of being prescribed these drugs increased by 6% more per month for the newly eligible group compared to documented patients (aOR 1.06; 95% CI 1.04–1.08; P < 0.001).
3. The Role of Therapeutic Classes: SGLT-2i vs. GLP-1 RA
The clinical implications of this shift are profound. SGLT-2 inhibitors (e.g., empagliflozin, dapagliflozin) have demonstrated significant reductions in hospitalizations for heart failure and the progression of chronic kidney disease (CKD). Given that the mean age of the undocumented group was 60 years—a period of high risk for cardiorenal complications—the tripling of SGLT-2i prescriptions represents a major preventative health milestone. Similarly, the 13-fold increase in GLP-1 RA prescriptions (e.g., liraglutide, semaglutide) offers benefits in atherosclerotic cardiovascular disease (ASCVD) risk reduction and significant weight management, which is critical in a population where obesity is highly prevalent.
Predicted probabilities for an SGLT-2 or GLP-1 prescription among patients with T2D in two Los Angeles FQHCs by immigration status and age, May 2021 to June 2023.
4. Persistence of Disparities in Younger Populations
A critical finding of the research was the continued disadvantage of the younger undocumented group (under age 50). While this group saw a slight rise in prescriptions due to general trends, their odds of receiving GDMT remained significantly lower throughout the study period (aOR 0.17 at baseline). This highlights that clinical need alone does not drive the adoption of high-cost therapies; insurance coverage is the primary gatekeeper. The “younger” group, while potentially having a lower immediate risk of heart failure than their 60-year-old counterparts, still faces long-term complications that could be mitigated by earlier access to these medications.
Expert Commentary
The findings from the California expansion offer a clear lesson in health policy: insurance status is a fundamental social determinant of health that dictates the quality of clinical care. From a mechanistic perspective, the rapid uptake of SGLT-2i and GLP-1 RA suggests that primary care providers (PCPs) in FQHCs were already aware of the benefits of these drugs and were likely waiting for a financial mechanism to provide them to their patients. This “pent-up demand” for evidence-based care is a hallmark of safety-net health systems.
However, several challenges remain. First, the cost-effectiveness of this expansion will depend on long-term data regarding the reduction of expensive emergency department visits and dialysis requirements. Second, while prescribing rates have equalized, we must ensure medication adherence. Undocumented populations face unique stressors, including housing instability and food insecurity, which can interfere with complex medication regimens. Furthermore, the global shortage of GLP-1 RAs may disproportionately affect safety-net clinics if supply chains favor private insurers over Medicaid providers.
Guideline perspectives (ADA/EASD) now emphasize that cost should not be a barrier to life-saving medications, yet the reality in many states remains far from this ideal. California’s model serves as a pilot for how state-level policy can bypass federal stagnation to improve local health outcomes.
Conclusion
The 2022 Medi-Cal expansion successfully removed the financial barriers that previously prevented older undocumented immigrants from accessing modern T2D therapies. The rapid convergence of prescription rates between documented and newly eligible undocumented patients suggests that policy interventions can effectively eliminate disparities in the quality of diabetes care. Future research should focus on whether this increased access translates into measurable reductions in cardiovascular events, renal failure, and overall mortality within this vulnerable population. Furthermore, expanding coverage to all age groups, regardless of status, remains a critical step toward achieving true health equity in the management of chronic diseases.
References
- Ro AE, Morales C, Jiang L, Choi JM, Tavares Kuhn N, Wu C. Changes in Type 2 Diabetes Medications Among Primary Care Patients After California’s 2022 Medicaid Expansion. Diabetes Care. 2026 Jan 1;49(1):78-85. doi: 10.2337/dc25-0787 IF: 16.6 Q1 . PMID: 41191813 IF: 16.6 Q1 .
- American Diabetes Association Professional Practice Committee. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2024. Diabetes Care. 2024;47(Supplement_1):S158-S178.
- Zinman B, Wanner C, Lachin JM, et al. Empagliflozin, Cardiovascular Outcomes, and Mortality in Type 2 Diabetes. N Engl J Med. 2015;373(22):2117-2128. PMID: 26378978 IF: 78.5 Q1 .
- Marso SP, Daniels GH, Brown-Frandsen K, et al. Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes. N Engl J Med. 2016;375(4):311-322. PMID: 27295739 .