The Winter 2021 issue of the Social Determinants of Health newsletter features strategies to improve care delivery by addressing SDoH; the impacts of COVID-19 on addiction and mental health; an article from Alexandra Schweitzer, senior fellow at the Mossavar-Rahmani Center for Business and Government at Harvard Kennedy School, on how SDoH programs are responding to the COVID-19 crisis; and the latest news and insights related to SDoH.