Methadone Maintenance Therapy (MMT) refers to the use of methadone to treat opioid addiction (such a heroin) when detoxification has been unsuccessful. Since 2015, USAID’s Sustainable HIV Response from Technical Assistance (SHIFT) activity has made significant strides in convincing local authorities to scale up MMT as a cost effective, evidence-based, and humane means to prevent HIV transmission and treat drug abuse. SHIFT has provided coaching and advocacy, with a consistent emphasis on sustainability in Nghe An and Dien Bien provinces. This work has resulted in achieving a sustainability milestone: both provinces recently committed to enroll a total of 7,400 MMT patients by 2019, a 90 percent increase from the 3,927 patients currently enrolled. So what? This MMT expansion by provincial governments is an example of host country sustainability.