The contract includes a 15-team no-trade list, according to Cap Friendly.
The 30-year-old Koskinen has made quite the impression since joining Edmonton on a one-year, $2.5-million deal last May. In 27 appearances for the Oilers this season, the Finn owns a 14-10-1 record with a 2.78 goals-against average and a .911 save percentage.
The netminder's latest flash of brilliance came Saturday night against the Calgary Flames when he put forward a candidate for save of the year.
Koskinen made four appearances for the New York Islanders during the 2010-11 season. Eight years later, he's officially found a home in the NHL.