Anticipating a growing need for health care during the COVID-19 pandemic, the Centers for Medicare and Medicaid Services expanded telemedicine coverage in the United States on March 6, 2020. In this study we used roughly thirty million Medicare fee-for-service claims to quantify outpatient telemedicine use before and after the Medicare telemedicine coverage waiver and to examine the association of telemedicine use with the Area Deprivation Index, a comprehensive measure of neighborhood socioeconomic disadvantage. Before the waiver, 0.42 percent of patients had at least one outpatient telemedicine visit, with no significant differences between people residing in the most versus the least disadvantaged neighborhoods. With the waiver, 9.97 percent of patients had at least one outpatient telemedicine visit, with the highest odds of utilization seen for people residing in the most disadvantaged neighborhoods. After adjustment, our data suggest that the coverage waiver increased access to telemedicine for all Medicare populations, including people residing in the most disadvantaged neighborhoods, although the odds of use were persistently lower with increasing age. Overall, these findings are encouraging, but they illuminate a need for targeted interventions to improve telemedicine access further.