From the official releases by the NHL and NHLPA:
FINAL TEAM USA 2016 WORLD CUP OF HOCKEY ROSTER
TORONTO (May 27, 2016) -- USA Hockey announced today its final 23-man roster for the World Cup of Hockey 2016, the best-on-best international hockey championship from Sept. 17 to Oct. 1, 2016, in Toronto. Seven players were added today, highlighted in bold. They join the 16 selected to the team on March 2.
F T.J. Oshie, Washington Capitals
F Zach Parise, Minnesota Wild
F Derek Stepan, New York Rangers
F Blake Wheeler, Winnipeg Jets
Eight teams -- Team Canada, Team Czech Republic, Team Finland, Team Russia, Team Sweden, Team USA, Team Europe and Team North America -- will compete in the two-week tournament, featuring more than 150 of the best players in the NHL. All tournament games will be played at Air Canada Centre in Toronto, home of the NHL Toronto Maple Leafs.
All eight teams competing in the World Cup of Hockey 2016 announced their rosters of at least 16 players today. Each of the teams will have a tournament roster of 23 players: 20 skaters and three goaltenders. The balance of each team’s roster will be announced no later than June 1, 2016.
The World Cup of Hockey 2016 is a joint effort of the National Hockey League and the National Hockey League Players’ Association, in cooperation with the International Ice Hockey Federation (IIHF). The eight teams are split into two Groups, Group A and Group B, for the Preliminary Round (Sept. 17-22), when each team will play its three Group opponents in a round-robin format. Placed in Group A are Team Canada, Team Czech Republic and Team USA, plus Team Europe, a pan-European roster of players from birth countries outside of the Czech Republic, Finland, Russia and Sweden. The four teams in Group B are Team Finland, Team Russia, Team Sweden and Team North America, a selection of the top players from Canada and the United States who are 23 or under as of Oct. 1, 2016.
The top two finishers in each of Group A and Group B will advance to the Semifinals (Sept. 24-25), where each qualifier will face an elimination game against a team from the other Group. The two Semifinal winners will meet in the Final, a best-of-three series on Sept. 27, Sept. 29 and, if necessary, Oct. 1.
Live coverage of all tournament games will be provided by Sportsnet and TVA Sports in Canada and ESPN in the United States. A complete broadcast schedule will be announced at a later date.