Colorectal cancer (CRC) screening rates have remained lower than the Healthy People 2010 goal, particularly among minority populations. This study aimed to examine the racial-ethnic trends in CRC screening and the continued impact of healthcare access indicators on screening differences after Medicare expanded coverage. The study used data from the Medicare Current Beneficiary Survey for 2000, 2003, and 2005. The sample was restricted to non-Hispanic whites, non-Hispanic blacks, and Hispanics. The primary outcome was the proportion of enrollees who underwent lower-gastrointestinal endoscopy within 5 years and/or home fecal occult blood test within 1 year. Over the 6-year period under study, the proportion screened increased among each of the three racial-ethnic groups, but lower proportions of blacks and Hispanics underwent screening compared with whites at each time point. Hispanic-white differences persisted but black-white differences narrowed in 2003 and widened in 2005. In each survey year, racial differences attenuated after adjustment for type of supplemental health insurance and disappeared after further adjustment for educational and income levels. Despite expanding benefits for CRC screening, which would be expected to disproportionally benefit racial and ethnic minorities, racial disparities in use of screening persist in part because of differences in the types of health insurance coverage, education, and income. There was a slight reversal of the initial attenuation of the black-white difference after the Medicare policy change. Efforts are needed to increase the reach of CRC screening to minority populations, particularly those lacking adequate health insurance coverage or with less education or income.