In 2020, cancer screenings declined, then rebounded, resulting in a cancer screening deficit. The significance of this deficit, however, has yet to be quantified from a population health perspective. Our study addresses this evidence gap by examining how the pandemic changed the timing of American adults' most recent cancer screen. We obtained population-based, cancer screening data from the Behavioral Risk Factor Surveillance System. Mammograms, pap smears, and colonoscopies were each specified as a variable of mutually exclusive categories to indicate the timing since the most recent screening (never, 0-1 years, 1-2 years, 3+ years). Our quasi-experimental design restricts the sample to adults surveyed in January, February, or March. We then leverage a quirk in the BRFSS implementation and consider adults surveyed in the second year of each survey wave as the quasi-treatment cohort. Next, we constructed Linear and Logistic regression models which control for exogenous sociodemographic characteristics, state fixed effects, and temporal trends. Our results suggest that the deficit in 2020 was largely due to a one year delay among adults who receive annual screening, as the proportion of adults reporting a cancer screen in the past year declined by a nearly identical proportion of adults reporting their most recent cancer screen 1-2 years ago (3\% to 4\% points). However, the relative change was higher for mammograms and pap smears (17\%) than colonoscopies (4\%). We also found some evidence that the proportion of women reporting never having completed a mammogram declined in 2020, but the mechanisms for this finding should be further explored with the release of future data. Our estimates for the pandemic's effect on cancer screening rates are smaller than prior studies, but because we account for temporal trends we believe prior studies overestimated the effect of the pandemic and underestimated the overall downward trend in cancer screenings across the country leading up to 2020.