First published in 1997 and now in its 24th year, Michigan Health Market Review analyzes the health care payer and provider markets in the state. The reports provide a comprehensive and objective analysis of strategies and key trends for the health insurers and provider systems in Michigan. Part One is now available and presents our analysis of the health insurers, their financial performance, enrollment and market share. It includes data on health plan financial results and enrollment in the first quarter of 2020, as the COVID-19 pandemic began to hit Michigan and other states. Later this year, the Part Two report will discuss the health systems, their financial results and their inpatient occupancy and payer mix. The reports also include an extended analysis of implementation of key elements of the Affordable Care Act in the state, including Medicaid expansion, Medicare Accountable Care Organizations and developments in the individual market.