Background: Medicaid expansion has led to earlier stage diagnoses in several cancers but has not been studied in hepatocellular carcinoma (HCC), a disease with complex risk factors. We examined the effect of Medicaid expansion on the diagnosis of HCC and associations with county-level social vulnerability. Methods: Patients with HCC <65 years of age were identified from the SEER database (2010–2016). County-level social vulnerability factors were obtained from the CDC SVI and BRFSS. A Difference-in-Difference analysis evaluated change in early-stage diagnoses (stage I-II) between expansion and non-expansion states. A Difference-in-Difference-in-Difference analysis evaluated expansion impact among counties with higher proportions of social vulnerability. Results: Of 19,751 patients identified, 81.5% were in expansion states. Uninsured status decreased in expansion states (6.3%–2.4%, p < 0.0001) and remained unchanged in non-expansion states (12.7%–14.8%, p = 0.43). There was no significant difference in the incidence of early-stage diagnoses between expansion states and non-expansion states. Results were consistent when accounting for social vulnerability. Conclusion: Medicaid expansion was not associated with earlier stage diagnoses in patients with HCC, including those with higher social vulnerability. Unlike other cancers, expanded access did not translate into higher utilization of care in HCC, suggesting barriers on a multitude of levels.