As we observe World AIDS Day on December 1, we remember those we’ve lost to the disease, reflect on the progress we’ve made in treating patients, and resolve to end the HIV and AIDS epidemic. SAMHSA’s role in ending HIV is vitally important because the people we are charged with caring for – those with a mental or substance use disorder – are disproportionately affected by HIV. The good news is we have seen great success in treating HIV infection over the past 20 years. In fact, a 20-year old who is diagnosed today with HIV can have a near normal life expectancy if they take antiretroviral medication every day and maintain an undetectable level of virus in their blood. We also know that someone with HIV and an undetectable viral load in their blood has almost no chance of transmitting the virus to their sexual partner or partners. Unfortunately there are still many barriers to overcome. Approximately 13% of Americans living with the disease don’t know they are HIV-positive. They, and many others who do know about their own diagnosis, are not receiving medical care, not taking their medications regularly, and not achieving an undetectable level of virus in their blood. It is important to identify everyone infected with HIV and link them with appropriate medical care. Further, people living with HIV frequently require treatment for mental illness or substance use disorders. There are significant correlations between HIV infection and behavioral health conditions, both substance use and mental health disorders. People with substance use disorders are at significant risk for acquiring HIV infection because of risk factors like sharing needles or risky sexual behavior. Similarly, people with mental illness are more likely to practice risky sexual behavior. That’s why behavioral health providers should be prepared to counsel their clients on the prevention of HIV, identify people with HIV infection through appropriate testing, and assure that they are linked to HIV care. Providing appropriate behavioral health services to these people will increase the chance that they will be adherent to their medication regimen and achieve an undetectable viral load, which will improve their well-being, extend their lives, and protect their sexual partners. Though we have made great strides in the prevention and treatment of HIV, there is still progress to be made to ensure that we are using the tools we have to prevent and treat HIV and AIDS. This progress, particularly among those most at risk, will require the involvement of a broad range of health care providers, including providers of behavioral health services. For more information, visit www.HIV.gov. If you or someone you love is concerned about HIV, please talk with your health care provider.