ObjectiveTo examine disparities in mental health (MH) service utilization, via in-person and telemedicine (ie, tele-MH), by individuals' race, ethnicity, and community socioeconomic status, among community-dwelling older adults with Alzheimer disease and related dementias (ADRD) before and after the expansion of the Centers for Medicare and Medicaid Services’ (CMS’s) telemedicine policy. DesignObservational study. Setting and ParticipantsA total of 3,003,571 community-dwelling Medicare beneficiaries with ADRD between 2019 and 2021 were included in the study. MethodsMultiple national data were linked. The unit of analysis was individual-quarter. Three outcomes were defined: any MH visits (in-person or tele-MH), in-person MH visits, and tele-MH visits per quarter. Key independent variables included individual race and ethnicity, the socioeconomic status of the community, and an indicator for the implementation of the telemedicine policy. Regression analyses with individual random effects were used. ResultsIn general, Black and Hispanic older adults with ADRD and those in socioeconomically deprived communities were less likely to have MH visits than white adults and those from less-deprived communities. In-person and tele-MH visits varied throughout the pandemic and across subpopulations. For instance, at the beginning of the pandemic, white, Black, and Hispanic older adults experienced 5.05, 3.03, and 2.87 percentage point reductions in in-person MH visits, and 3.53, 1.26, and 0.32 percentage point increases in tele-MH visits (with P < .01 for racial/ethnic differences), respectively. During the pandemic, the increasing trend in in-person MH visits and the decreasing trend in tele-MH visits varied across different subgroups. Overall, racial and ethnic differences in any MH visits were reduced, but the gap in any MH visits between deprived and less-deprived communities doubled during the pandemic (P < .01). Conclusions and ImplicationsTelemedicine may have provided an opportunity to improve access to MH services among underserved populations. However, although some disparities in MH care were reduced, others widened, underscoring the importance of equitable health care access strategies to address the unique needs of different populations.