Bernie Sanders vs. Verizon: Who is right?

Recently, Sanders made a claim that Verizon doesn't pay any taxes. A simple google search will show that this claim is supported by a wide variety of sources, many from several years ago (before politics might add extra biases) (1, 2, 3), so there must be at least some truth to the claim.

However, Verizon's CEO recently made a statement that Bernie is entirely incorrect, and a look a Verizon's latest SEC 10-K filing seems to agree with the CEO's claim. (For those who don't want to search through that monotonous document, the "total income tax provision" noted for 2015 is $9865 million).

This should be a cut-and-dry issue, no? The amount of money paid from Verizon to the federal government in 2015 should should be a simple fact, but I am having a lot of trouble finding any sources which can put this to rest.

tldr: How much money did Verizon actually pay to the federal government in 2015?

Edit: Thanks for the replies, everybody. I learned quite a bit from the discussion, and I'll summarize some of my conclusions up here for posterity.

• Ultimately, Verizon is paying its federal taxes, as far as I can tell from the 10-K, or as far as most of the commenters here can tell.
• Bernie isn't directly lying, however. As pointed out by u/jacksonmills, Verizon New York has not paid any taxes in a while, largely due to repeated losses.
• As noted by multiple people, most of the reason that corporations avoid paying taxes in a given year is Tax loss carryforward, which explains some of the suspect years.