In December 2006, the M·A·C AIDS Fund announced an initiative addressing HIV-prevention and awarded $2.4 million to 11 organizations. Why HIV Prevention? AIDS cannot be cured, but it can be prevented. Two and a half decades into the epidemic, however, we know too little about why individuals do not practice HIV prevention and how barriers like poverty and domestic violence hinder a person’s ability to prevent infection. For instance, many men – maybe most – will not use a condom. How can we empower men and women to insist that their partner use one? The private sector, particularly in the U.S. – the richest country in the world – must step up its commitment to help support prevention efforts. The same is true for the public sector. In 2004, only 5% of federal dollars for AIDS in the U.S. was targeted at prevention. Anyone can become HIV infected if they do risky things and do not practice HIV prevention. Clearly, though, HIV infection is concentrated in certain groups more than others because of factors like poverty and high-risk behaviors. But such concentration is not unstoppable or unsolvable. Through this initiative, the M·A·C AIDS Fund seeks to help a wide range of communities in their prevention efforts. We want to enable them to have frank conversations about how people behave and why, and then to determine and test ways to help their members practice prevention.