In 2018, he was elected to be the Lieutenant Governor of Hawaiʻi. As Lieutenant Governor, he saw the need for real solutions on homelessness and helped build “kauhale” communities and the H4 clinic to provide housing and healthcare for those most in need. In 2019 when the measles epidemic hit, he led a team of more than 75 doctors, nurses, and other medical professionals on an emergency mission to Western Samoa. His team successfully vaccinated 37,000 people. Just a few months later when the COVID pandemic spread to Hawai‘i, Governor Green was appointed as the COVID liaison between the state and healthcare communities to coordinate pandemic preparedness, response, and mitigation efforts. As a result of his leadership, these critical emergency efforts resulted in Hawaiʻi having the nation’s lowest COVID-19 fatality rate.