Background: The coronavirus (COVID-19) pandemic transformed norms and approaches to delivering cancer care in the US throughout 2020. While initial reports in regional and single institution studies suggest postponement or modification of cancer treatments, limited evidence exists on the long-term national impact of COVID-19 on cancer treatment throughout the year. Methods: Using de-identified OptumLabs Data Warehouse data, which includes data from the Optum Cancer Guidance Program’s electronic prior authorization (ePA) platform, we compared monthly rates (per 100,000 person-months) of requests for authorization for insurance coverage of systemic cancer therapy in January-December 2020 (COVID) versus January-December 2019 (non-COVID). Results: We identified a total of 94,726 prior-authorization requests for chemotherapy in 2020 compared to 106,272 requests in 2019, indicating a 10.8% overall decline during the pandemic. Prior-authorization request rates were 6.3% higher in March 2020 as many stay-at-home orders were implemented across states (Table). Prior authorization requests then significantly declined in April and May 2020 (3.3% and 14.4% lower rates in 2020 vs. 2019) during the stay-at-home orders before briefly increasing again in June. As COVID-19 infections and deaths increased throughout the fall, requests for prior-authorization significantly declined in each month from August through December 2020. Conclusions: The COVID-19 pandemic led to significant overall declines in requests for prior authorizations for chemotherapy in 2020 versus 2019. While requests rebounded somewhat in early spring and summer of 2020, rates were markedly lower, relative to those in 2019, during COVID-19’s second wave. Overall, these results suggest continued modifications or delays in cancer treatment that may result in worse outcomes for individuals with cancer in 2020 and should be evaluated in future studies.

*Rate per 100,000 person-months.