As of April 2014, there was a 125-player tie for the right to be called the lowest paid player in the NHL at $550,000 dollars per year. This is because the NHL and the NHLPA have a minimum salary for NHL players, which can vary by season. This means that the absolute minimum amount of money any NHL player can make for a contract is $550,000.
There are, however, players being paid less than $550,000 a year. These are players that are owed money from old contracts and have since retired or left the NHL. An example is former Thrashers and Devils star Ilya Kovulchuk, who is owed $250,000 over the next five seasons due to a contract buyout.