Gionta, 39, played in all five of the U.S. team's games in South Korea as the Americans advanced to the quarterfinals before being eliminated by the Czech Republic. He held off signing with an NHL team in free agency last summer to pursue an opportunity to compete at the Olympics.
He played for the Buffalo Sabres last season, serving as captain and finishing with 15 goals and 20 assists in 82 games.
He played with Bruins assistant Jay Pandolfo on the Devils team that won the Stanley Cup in 2002-03.
Gionta played collegiately at Boston College and is the Eagles' all-time leading scorer with 123 goals in 164 games.
The Bruins also placed defenseman Paul Postma on waivers.
The Associated Press contributed to this report.