What is already known about this topic? Routine health care services have been disrupted during the COVID-19 pandemic. What is added by this report? During the first week after the national COVID-19 emergency declaration in March 2020, weekly vaccination rates among Medicare beneficiaries aged ≥65 years declined by 25%–62%, compared with the corresponding period in 2019. By mid-April, vaccination rates in this group reached nadirs of 70%–89% below 2019 rates. Rates partially recovered gradually during May–July 2020. What are the implications for public health practice? Vaccination providers should emphasize the importance of routine adult vaccination to their patients and ensure the safe provision of vaccines to protect older adults from vaccine-preventable diseases during the ongoing COVID-19 pandemic.