In 2012, UNAIDS and other organizations joined together to launch the Treatment 2015 initiative, which aimed to redouble efforts to achieve the global target of reaching 15 million people with HIV treatment by 2015. Determined to achieve a highly ambitious global treatment target by the agreed deadline, it called for concerted global action to increase the speed of HIV treatment scale-up, enhance the programmatic focus on those most in need, and foster innovation in HIV testing and treatment approaches. This report celebrates the world’s achievement of this historic milestone, which is saving more lives than ever before. As this report reveals, we have indeed learned how to do better in bringing HIV treatment to those who need it. For the first time, a majority of people living with HIV know their HIV status. Antiretroviral regimens are more durable, tolerable and easier to take than ever before. Treatment programmes are becoming even more efficient and focused. In recent years, powerful innovations have emerged to improve the reach and impact of treatment programmes, including new community-based models for delivery of antiretroviral therapy. What was once thought impossible has become possible. There still is much to be done to end the AIDS epidemic by 2030.