The 32-year-old has made 129 white-ball appearances for New Zealand and will feature in next month's limited-overs series against India before heading to Australia under a BBL deal that has yet to be announced.
He joins Finn Allen, Lockie Ferguson, Adam Milne and Tim Seifert among players who have opted for the casual contract system, which allows them to play in high-paying Twenty20 leagues while remaining available for national duty.
"The upcoming India series is one all us players are really excited for, and I'm committed wholeheartedly to performing in that series," Chapman said, thanking NZC for their support.
His move off the central contract list has opened the door for fast bowler Matt Fisher, who has been awarded a full contract for the first time.