Accident Compensation Act 2001, ss 17, 22
You’re covered by ACC if you’re injured while you’re overseas. You have to be “ordinarily resident” in New Zealand, which means that you have a permanent home here (or your partner or child is a resident). However, you’re not covered if you have been overseas for more than six months, or if when you left New Zealand you had intended to be out of the country for more than six months (unless you were overseas for work reasons and intended to come back to live in New Zealand).