IMPORTANCE: Despite the benefits of high-technology therapeutics, inequitable access to these technologies may generate disparities in care. OBJECTIVE: To examine the association between zip code-level racial, ethnic, and socioeconomic composition and rates of transcatheter aortic valve replacement (TAVR) among Medicare patients living within large metropolitan areas with TAVR programs. DESIGN, SETTING, AND PARTICIPANTS: This multicenter, nationwide cross-sectional analysis of Medicare claims data between January 1, 2012, and December 31, 2018, included beneficiaries of fee-for-service Medicare who were 66 years or older living in the 25 largest metropolitan core-based statistical areas. EXPOSURE: Receipt of TAVR. MAIN OUTCOMES AND MEASURES: The association between zip code-level racial, ethnic, and socioeconomic composition and rates of TAVR per 100 000 Medicare beneficiaries. RESULTS: Within the studied metropolitan areas, there were 7590 individual zip codes. The mean (SD) age of Medicare beneficiaries within these areas was 71.4 (2.0) years, a mean (SD) of 47.6% (5.8%) of beneficiaries were men, and a mean (SD) of 4.0% (7.0%) were Asian, 11.1% (18.9%) were Black, 8.0% (12.9%) were Hispanic, and 73.8% (24.9%) were White. The mean number of TAVRs per 100 000 Medicare beneficiaries by zip code was 249 (IQR, 0-429). For each $1000 decrease in median household income, the number of TAVR procedures performed per 100 000 Medicare beneficiaries was 0.2% (95% CI, 0.1%-0.4%) lower (P = .002). For each 1% increase in the proportion of patients who were dually eligible for Medicaid services, the number of TAVR procedures performed per 100 000 Medicare beneficiaries was 2.1% (95% CI, 1.3%-2.9%) lower (P < .001). For each 1-unit increase in the Distressed Communities Index score, the number of TAVR procedures performed per 100 000 Medicare beneficiaries was 0.4% (95% CI, 0.2%-0.5%) lower (P < .001). Rates of TAVR were lower in zip codes with higher proportions of patients of Black race and Hispanic ethnicity, despite adjusting for socioeconomic markers, age, and clinical comorbidities. CONCLUSIONS AND RELEVANCE: Within major metropolitan areas in the US with TAVR programs, zip codes with higher proportions of Black and Hispanic patients and those with greater socioeconomic disadvantages had lower rates of TAVR, adjusting for age and clinical comorbidities. Whether this reflects a different burden of symptomatic aortic stenosis by race and socioeconomic status or disparities in use of TAVR requires further study.