"Todd's progress over the past 12 months has been exciting. When fit, he made the most of his opportunities in both test and ODI cricket," Larsen said.
The criteria used for settling on the top 20 is ranking players across all three forms of the game, with test cricket getting twice the weighting of the two short form versions.
Astle's addition means there are three spinners in the 20, alongside legspinner Ish Sodhi and left arm allrounder Mitchell Santner, currently working through a lengthy layoff for a knee injury.
The only specialist wicketkeeper in the group is BJ Watling, but batsman Tom Latham, with considerable prowess keeping in the short forms, is in there.
There are six fast bowlers, Trent Boult, who is sure to be among the top three players in terms of the size of his contract, Tim Southee, Neil Wagner, Adam Milne, Matt Henry and Lockie Ferguson – who received a belated contract last season when Mitch McClenaghan, who was in the original list, opted out to pursue more T20 league opportunities.
Larsen said there had been some tough calls but that fringe players will continue to be watched to push their case through the New Zealand A and domestic programmes.
Among those to miss out were Wellington wicketkeeper Tom Blundell, who scored a century on his test debut against the West Indies, promising batsman-wicketkeepers Glenn Phillips from Auckland and Northern Districts' Tim Seifert, specialist batsman Tom Bruce and experienced seamer Doug Bracewell, both from Central Districts.
Just who sits in which payment band is never revealed but the top dollar will clearly go to national captain Kane Williamson, with the likes of Boult, Ross Taylor and Tim Southee probably on the next step.
Those who play all three forms regularly are generally financially better off.
The top payment is likely just over $200,000, dropping in increments down to the bottom three or four players who will receive close to $90,000. Match fees kick in on top of that while the captain also receives a separate payment for that role.
New Zealand's home international programme won't be released until next month, but will include visits from Sri Lanka, India and Bangladesh, preceded by a lengthy trip to the United Arab Emirates to play Pakistan.
The contracts kick in from August 1.
The 20 contracted players for 2018-19 are: Kane Williamson, Corey Anderson, Todd Astle, Trent Boult, Lockie Ferguson, Colin de Grandhomme, Martin Guptill, Matt Henry, Tom Latham, Adam Milne, Colin Munro, Henry Nicholls, Jeet Raval, Mitchell Santner, Ish Sodhi, Tim Southee, Ross Taylor, Neil Wagner, BJ Watling, George Worker.
