Background: Prior studies have demonstrated disparities in access to cardiovascular procedures on the basis of socioeconomic status (SES). Left ventricular assist devices (LVADs) are used as a bridge to transplant or as destination therapy in heart failure. Our objective was to determine whether there is a relationship between SES and receipt or outcomes of LVAD implementation. We assessed whether Medicaid expansion was associated with an increase in LVAD implantation among likely poor individuals. Methods: We studied all patients <85 years of age admitted with heart failure or cardiogenic shock in the State Inpatient Database (SID) in AZ, AK, CO, FL, MA, MD, MI, NE, NJ, NV, NY, VT, WA, WI, and IA between 1/1/2012 and 9/30/2015. Elixhauser comorbidities, age, gender and hospital characteristics were used for multivariate regression analyses. Difference-in-difference analyses were conducted to evaluate changes in Medicaid expansion versus non-expansion states. Results: Among 889,377 patients, 64.6% were > 65 years old; 43.3% were women; and 64.2% were Caucasian. Overall, 0.42% of patients received LVADs. After adjusting for age, gender, comorbidities, and hospital characteristics, African Americans (odds ratio [OR] 0.72, 95% CI 0.65-0.80) and Hispanics (OR 0.62, 95% CI 0.53-0.72) were less likely to receive LVADs compared to Caucasians. Compared to privately insured patients, those with Medicare (OR 0.72, 95% CI 0.65-0.79), Medicaid (OR 0.43, 95% CI 0.38-0.49), and uninsured (OR 0.10, 95% CI 0.06-0.15) were less likely to receive LVADs. Patients residing in the lowest-income ZIP codes were less likely to receive LVADs (OR=0.74, 95% CI 0.67-0.82) than those in higher-income quartiles. Among patients who received LVADs, African Americans (OR 0.75, 95% CI 0.73-0.77) and Hispanics (OR 0.84, 95% CI 0.81-0.87) had lower risk-adjusted mortality compared to Caucasians. Patients with Medicaid (OR 0.94, 95% CI 0.90-0.99) had lower mortality, uninsured patients had higher mortality (OR = 1.23, 95% CI 1.16-1.31), and Medicare patients had similar mortality (OR 1.01, 95% CI 0.98-1.05) compared to privately insured patients. Mortality did not differ by ZIP code income. The rate of LVAD implantation among likely poor patients (Medicaid, uninsured, or low-income ZIP) at baseline in Medicaid expansion states was 0.35%; this increased to 0.40% post-expansion (p=0.037). In non-expansion states, the baseline rate was 0.23%, which remained unchanged post-expansion at 0.23% (p=0.88), for a difference-in-differences of 0.05% (p=0.47). Conclusion: Patients with low income, no insurance or Medicaid insurance, and racial/ethnic minorities were less likely to receive LVADs. Among patients who received LVADs, African Americans and Hispanics had lower in-hospital mortality. Medicaid expansion was not associated with a differential change in access to LVADs among likely poor patients.