The Covid-19 crisis provides for a unique opportunity to empirically test a commonly held assumption in the literature that crises centralize and concentrate authority in national governments. The Subnational Government Epidemic Authority Index (SGEAI) traces self-rule and shared rule in relation to restrictive and preventive measures before and during the Covid-19 crisis in 27 European countries. The SGEAI reveals that no significant centralization has taken place in relation to shared rule and preventive measures, but subnational governments lost self-rule in countries that did have pre-crisis epidemic competences whereas they gained self-rule in countries that did not have epidemic competences. These strikingly contrasting results can be explained by the regulatory nature of restrictive measures which require limited decentralization for monitoring and sanctioning compliance to restrictions. In addition, the benefits of decentralization could also be achieved by territorial differentiation–i.e. adjusting restrictions to locally differing infection rates and public health care capacities—or RTV-differentiation –i.e. adjusting restrictions to people who pose a lower risk for further spreading an infectious disease because they were recovered (R), tested negative (T), or were vaccinated (V).