Objectives: Many countries have continued to experience a higher-than-expected number of deaths following the peaks in mortality observed in the first year of the Covid-19 pandemic. This scoping review aims to identify the different explanations proposed for sustained higher-than-expected mortality beyond the first pandemic year. Study design: Scoping review Methods: A systematic search of databases and grey literature sources was completed to identify English-language records proposing or investigating hypotheses for higher-than-expected mortality from April 2021 onwards in (sub)populations of high-income countries. Papers focused on survival following a diagnosis or intervention were excluded. Results were summarised narratively, and existing research prioritisation frameworks were adapted and applied to identify the hypotheses proposed as highest priority for further research. Results: Seventy eligible papers were identified. Most were opinion pieces or simply presented trends; few included investigation of suggested hypotheses. Numerous explanations for higher-than-expected mortality were proposed, with hypotheses relating to direct Covid-19 mortality, sequalae of Covid-19 infection, the health service impacts of the pandemic, wider pandemic impacts and socioeconomic factors identified as highest-priority for further research. Conclusions: The causes of continued higher-than-expected mortality are likely to be multiple and potentially interactive. This review will help to shape research into current mortality trends, with a critical understanding of this topic essential for achieving evidence-informed policy.