Lessons Learned: The Varied Responses of Massachusetts' Local Health Departments During the COVID-19 Pandemic.

Context: Massachusetts' decentralized public health model holds tightly to its founding principle of home rule and a board of health system established in 1799. Consequently, Massachusetts has more local health departments (n = 351) than any other state. During COVID-19, each health department, steeped in centuries of independence, launched its own response to the pandemic.