"You'll get a bit of a sense where there's work that we are carrying over [from last term], where there's new work, what their responsibilities will be, what they are agreeing to support and in some cases what they are not agreeing to support."
Mr Key would not reveal what ministerial positions would be handed out but all but confirmed Act's John Banks and United Future's Peter Dunne would be ministers.
"I could not see why that would not be the case," he said.
Act's sole MP Mr Banks said the party had no "bottom lines" in their agreement with the National Party, telling Radio New Zealand the deal underpins some the party's important values.
He dismissed the suggestion he was simply a "poodle for the National Party".
"I find that rather gratuitous and it could even be insulting. I'm not a poodle for anyone."