The 2014 NFL salary cap was set Friday at $133 million, up from $123 million last season, and league sources told ESPN NFL Insider Adam Schefter it could break $150 million by 2016.
The 2014 number is the highest cap in league history, surpassing $127.997 million in 2009.
And cap numbers are expected to continue to climb, surpassing $140 million next year before another significant rise in 2016, sources said.
Teams must be compliant with the cap by March 11, when the free-agency period begins, and some have started cutting players to create cap savings.
NFL teams can carry over unused salary cap room from the previous league year, and the NFLPA said in a release Friday the average carryover for those teams that elected to do so was $6.1 million.
The league's salary cap is calculated by taking a percentage of all projected NFL revenues, subtracting projected benefits for the season, and dividing by 32 teams.
Information from The Associated Press was used in this report.