Clinical guidelines have endorsed early palliative care for patients with advanced malignancies, but receipt remains low in the US. This study examined the association between Medicaid expansion under the Affordable Care Act and receipt of palliative care among patients newly diagnosed with advanced-stage cancers. Using the National Cancer Database, we found that the percentage of eligible patients who received palliative care as part of first-course treatment increased from 17.0 percent preexpansion to 18.9 percent postexpansion in Medicaid expansion states and from 15.7 percent to 16.7 percent, respectively, in nonexpansion states, resulting in a net increase of 1.3 percentage points in expansion states in adjusted analyses. Increases in receipt of palliative care associated with Medicaid expansion were largest for patients with advanced pancreatic, colorectal, lung, and oral cavity and pharynx cancers and non-Hodgkin lymphoma. Our findings suggest that increasing Medicaid coverage facilitates access to guideline-based palliative care for advanced cancer, and they provide additional evidence of benefit in cancer care from states' expansion of income eligibility for Medicaid.