The Medicare Current Beneficiary Survey (MCBS) has been used by policymakers and research analysts to provide information on a wide array of topics about the Medicare Program. Nonresponse bias is potentially one of the most important threats to the validity of the estimates from the MCBS. In this article we present results of our methodological study that analyzes the impact of nonresponse on MCBS estimates, including initial round unit nonresponse, panel attrition, and item nonresponse. Our findings indicate that for most of the measures studied, the bias caused by differences between nonrespondents and respondents in the MCBS was substantially reduced or eliminated by the nonresponse procedures currently employed.
