Undetectable = Untransmittable (U=U) means that people living with HIV (PLHIV) who adhere to their antiretroviral therapy (ART) daily, as prescribed, can maintain an undetectable viral load and will not be able to transmit the virus to others through sexual intercourse. Spreading the U=U message is part of the HIV prevention strategy to reduce new HIV infections, provide hope, and enhance the lives of persons living with HIV.