Full details of the agreement have not yet been released, but it reportedly will see the NHL season increase by two games to 84 contests per club with two fewer pre-season games to be played.
Another reported tweak in the contract will see the maximum player contract length reduced by one year to seven seasons.
Players could re-sign with their clubs for seven campaigns or join a new team as a free agent for up to six seasons.
Negotiators for the two sides agreed to the new deal in June, shortly before the NHL draft.
It was ratified Tuesday after a vote of the players association full membership and the NHL Board of Governors.
"The partnership between the Players’ Association and the League is stronger than it ever has been and working together under this agreement presents a fantastic opportunity to continue to grow the game," NHL commissioner Gary Bettman said in a statement.
Marty Walsh, executive director of the NHLPA, said the agreement "will allow for the cntinued worldwide growth of the game".
Talks between Bettman, Walsh and their top negotiators had begun in March.
The new deal follows a 10-year agreement signed in 2013 and extended in 2020.
