BackgroundThe adult social care sector is being increasingly outsourced to for-profit providers, but the impacts of privatisation on service quality and resident outcomes are unclear. During the COVID-19 pandemic, for-profit providers have been accused of failing their residents by prioritising profits over care, prevention, and caution, which has been reported to result in a higher prevalence of COVID-19 infections and deaths in for-profit care homes. Although many of these reports are anecdotal or based on news reports, there is a growing body of academic research investigating ownership variation across COVID-19 outcomes, which has not been systematically appraised and synthesised.ObjectivesTo identify, appraise, and synthesise the available research on ownership variation in COVID-19 outcomes (outbreaks, infections, deaths, shortage of personal protective equipment (PPE) and staff) across for-profit, public, and non-profit care homes for older people, and to update our findings as new research becomes available.DesignLiving systematic review.MethodsThis review was prospectively registered with Prospero (CRD42020218673). We searched 17 databases and performed forward and backward citation tracking of all included studies. Search results were screened and reviewed in duplicate. Risk of bias (RoB) was assessed in duplicate according to the COSMOS-E guidance. The results were synthesised according to RoB, model adjustment, and country context and visualised using harvest plots.ResultsTwenty-eight studies across five countries were included, with 75% of included studies conducted in the Unites States. For-profit ownership was not consistently associated with a higher probability of COVID-19 outbreaks across included studies. However, there was compelling evidence of worse COVID-19 outcomes following an outbreak; with for-profit care homes having higher rates of accumulative infections and deaths. For-profit providers were also associated with shortages in PPE, which may have contributed to the higher incidence of infections and deaths.Chain affiliation was often found to be correlated with higher risk of outbreaks, but not consistently associated with an elevated number of deaths and infections. Private equity ownership was not consistently associated with worse COVID-19 outcomes.ConclusionFor-profit status was a consistent risk factor for higher cumulative COVID-19 infections and deaths. Thus, ownership among providers may be a key modifiable factor which can be regulated to improve health outcomes in vulnerable populations and reduce health disparities. This review will be updated as new research becomes published, which may change the conclusion of our synthesis.