Allrounder De Grandhomme, who was born and played under 19 cricket for Zimbabwe, made his Test debut against Pakistan last November taking six wickets in the first innings.
The hard-hitting right-handed batsman has played in six Tests, nine ODIs and eight T20Is for the Black Caps.
Opening batsman Raval made his international debut in the same match as De Grandhomme and has gone on to become the Kiwis’ regular opener in the longest format, playing all the games in their last home summer.
The left-hander averages just more than 44 after seven Tests and has struck five half-centuries but hasn’t as yet hit a ton.
The 33-year-old Broom made his Test debut against South Africa in March this year after being a proven performer over many years in New Zealand’s domestic system and he has become a regular in national squads in limited-overs cricket.
Selector Gavin Larsen said: “Colin made a breakthrough last summer and is rated well in all three formats.
“Jeet’s Test numbers speak for themselves, and Neil, as well as averaging 43 in ODI cricket since his recall, is also seen as viable cover for the Test team’s middle-order.”
Wicketkeeper Luke Ronchi, who retired from international cricket in June, spinner Mark Craig and seamer Doug Bracewell were the players not to have their contracts renewed.
New Zealand central contracts list: Corey Anderson, Trent Boult, Neil Broom, Colin de Grandhomme, Martin Guptill, Matt Henry, Tom Latham, Mitchell McClenaghan, Adam Milne, Colin Munro, Henry Nicholls, James Neesham, Jeet Raval, Mitchell Santner, Ish Sodhi, Tim Southee, Ross Taylor, Neil Wagner, BJ Watling, Kane Williamson, George Worker.