53. Can existing contracts be renegotiated?
A contract for four or more seasons can be renegotiated after the third anniversary of its signing, extension, or renegotiation that increased any season's salary by more than 8%. Contracts for fewer than four seasons cannot be renegotiated. A contract cannot be renegotiated between March 1 and June 30 of any year. Only teams under the cap can renegotiate a contract, and the salary in the then-current season can be increased only to the extent that the team has room under the cap. Raises in subsequent years are limited to 10.5% of the salary in the first renegotiated season. The renegotiation may not contain a signing bonus. Contracts cannot be renegotiated downward (players can't take a "pay cut" in order to create salary cap room for the team) or to contain fewer seasons.
Again, a team over the salary cap cannot renegotiate a contract. An interesting case of this was Shawn Kemp with the Sonics. Kemp, who was unhappy with his contract and wanted to renegotiate, could not get a larger contract from the Sonics because they were over the cap. Kemp forced a trade to Cleveland, who was far enough under the cap at the time to give him the large contract he wanted. Kemp's contract was renegotiated soon after the trade.