On March 28, 2017 I noticed that the Patriots salary cap number on the NFLPA site decreased by $4.5 million since March 27th. So I asked a couple of sources to see if the Patriots adjusted cap number had decreased or if the cap numbers for a player or two (most likely Amendola or Nate Solder). They were able to confirm that the Patriots adjusted cap number had decreased from $173,298,888 to $168,798,888.
Why the decrease?
When the new CBA was agreed upon in 2011, the Salary Cap saw a reduction and, for the first few years, stagnation.