BACKGROUNDRecent treatment advances have greatly improved the prognosis of patients with multiple myeloma. However, some of these newer, more effective treatments are intensive and expensive and their use remains low, particularly among black patients. METHODSIn the current study, the authors reviewed the use patterns of stem cell transplantation and bortezomib using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. RESULTSAfter controlling for overall health and potential access barriers, black patients were found to be 37% (P<.0001) less likely to undergo stem cell transplantation, and 21% (P<.0001) less likely to be treated with bortezomib. Moreover, the authors found that the underuse of these treatments was associated with a 12% increase in the hazard ratio for death among black patients (P=0.0007). CONCLUSIONSEliminating health disparities, a current focus of US public policy, is highly complex, as illustrated by the results of the current study. In patients with multiple myeloma, treatment disparities are not completely explained by potential access barriers. Additional factors, such as structural barriers in the health care system and individual decision making among black and white patients, must be explored to fully explain the disparity. Cancer 2017;123:1590-1596. (c) 2017 American Cancer Society. In patients with multiple myeloma, treatment disparities are not completely explained by potential access barriers. Additional factors must be explored to fully explain the disparity.