McNichol reportedly had disclosed Saturday he was leaving but the team's announcement officially marks the end of one of the most successful seasons for U.S. skiers, who won a total of five titles in 2008.
"Phil has done an unbelievable job with the U.S. Ski Team," said team Alpine Director Jesse Hunt. "The World Cup results we've had in the last six years under his leadership are significant.
"We're disappointed to see Phil leave, but I also understand his wish to spend more time with his family. As an American team that competes primarily in Europe, it's a tough task and Phil has shown great perseverance for many years. And he's developed a program that can carry on the tradition of athletic success."
"It's good to leave when the guys are doing well and the team is in a good place," McNichol said. "The whole organization is moving in the right direction. I wanted to leave it better than when I started."