When cities decline, they can take decades to recover, if they ever do. McKinsey’s research suggests that many U.S. cities could experience a steady downward trajectory without effective intervention. We find that some cities may take years to bounce back from the impact of the COVID-19 pandemic on real estate and the economy. But such a doom loop is far from inevitable; there are many examples of success that we can learn from. Indeed, while U.S. cities will differ from what they were before COVID-19, this is also an opportunity to shape them into more vibrant and equitable places.