For nine years, the government has relied on the color-coded terrorism alert system, a system that some say was ambiguous at best.
The new system has only two threat levels -- "elevated" and "imminent" -- and it promises more specific details on actual threats.
The Department of Homeland Security heard from local leaders. Merni Fitzgerald with Fairfax County talked about the importance of getting out one simple message.
"During a time of stress, people can only take in a certain amount of information what should they do, where can they go," she says.
Charles Marino with the Department of Homeland Security says the messages will be specific.
"If we can do it without jeopardizing ongoing investigations and sources, we hope to provide details that will be specific and effective," he says.
Local governments will forward the alerts through websites and social media such as Facebook and Twitter.