Sodhi, Munro, Nicholls and Worker replace Brendon and Nathan McCullum, who have both retired from all international cricket, and Grant Elliott, who is now only available for T20Is.
The contracts run from August 1 2016 through to July 31 2017, and has been increased from 20 to 21 players after an agreement was reached with the country’s players’ association.
Batsman Nicholls and all-rounder Worker both made their international debuts in the past year.
Black Caps selector Gavin Larsen said of the list: “We’ve built a strong group of core players over the past couple of years and that’s been a key factor to the consistency of the team’s performance.
“When we’ve brought new players into the group, we’ve been really happy with how they’ve adapted and performed on the international stage.
“Henry and George have made bright starts to their Black Caps careers and we look forward to watching their ongoing development.
“After missing out last year, Ish and Colin have both worked extremely hard on their game, as we saw with their performances for us in the shorter formats this summer. They thoroughly deserve their contracts.
“It’s also exciting to see Ish make his way back into the Test squad for the upcoming series in Africa.”
The Kiwis next go to Africa to face Zimbabwe and South Africa in Test series in July and August.
New Zealand Contracted players for 2016-17:
Corey Anderson, Trent Boult, Doug Bracewell, Mark Craig, Martin Guptill, Matt Henry, Tom Latham, Mitchell McClenaghan, Adam Milne, Colin Munro, James Neesham, Henry Nicholls, Luke Ronchi, Mitchell Santner, Ish Sodhi, Tim Southee, Ross Taylor, Neil Wagner, BJ Watling, Kane Williamson, George Worker