As of 2018, 84% of low- and middle-income countries, and all of the UNAIDS Fast-Track countries, had adopted a test and treat policy. If current commitments are kept to, by the end of 2020, 92% of all low- and middle-income countries will have adopted a test and treat strategy.These changes have contributed to a significant increase in the number of people on ART, which increased by 4.5 million in just two years between 2015 and 2017: from 17.2 million to 21.7 million.