The 32 NFL teams have a collective $9 billion in revenue and those teams are NOT tax exempt. The money that is given over to the league (for Administration) is not taxed. In 2012, the league itself spent more money in operation than they took in revenue so they would have reported a loss and paid little if no taxes anyway.
"The NFL's 990 federal tax form, filed to the IRS in 2012 and available for view at the nonprofit watchdog site GuideStar, shows that during the previous year the league office received $255.3 million in revenue (almost all of it via annual dues paid by the teams) while it spent a total of $332.9 million, including $2.3 million in grants given to community groups like United Way ($15,898) and March of Dimes ($10,000).
Using its tax-exempt revenues, the league office also paid $29.4 million in salary to NFL Commissioner Roger Goodell, for which he owed income taxes, and it paid $35.9 million to the New York City construction firm J.T. Magen & Company, which built out a new office space for the NFL bosses and their 1,546 employees after their previous lease expired and they opted to relocate to another part of Manhattan.
While the money to pay for those expenses was derived from tax-exempt revenues, the league does not claim an off-setting federal deduction as do for-profit corporations for any business expenses it incurs such as moving, remodeling, travel or rent, Spector said. "
http://www.nbcnews.com/business/legal-procedure-critics-cry-foul-nfl-defends-nonprofit-status-8C11412804