Hospital data for covid-19 surveillance, planning and modelling are challenging to find well into the pandemic. Data for new covid-19 admissions are particularly challenging to find. Accurate hospital data are the best source of information for short-term forecasts of health care capacity, and they improve long-term covid-19 models that are typically based on cases. We describe the role of hospital data for studying covid-19, why admission data are hard to find, and how improved data infrastructure can meet surveillance and planning needs over the next year. Critical infrastructure includes a well-maintained list of patients hospitalized with covid-19 that is integrated with public health information systems.