[1] It was a mutual insurance company, meaning it was owned by its policy holders, until it was bought out by IAG New Zealand in 2011, following the 2011 Christchurch earthquake.

However, large losses led to a $76 million shortfall of its $198.6 million regulatory capital requirement and so forced the controversial[3][4] sale of AMI to IAG New Zealand, the local arm of Australia and New Zealand's largest insurance company, Insurance Australia Group.

It was responsible for settling claims by AMI policyholders for Canterbury earthquake damage that occurred before 5 April 2012.

[5] Perceived poor performance of that organisation led to some protests[6][7] and a lawsuit,[8] but a large percentage of the easier repairs were actioned despite a period of work outstripping resources in post-quake Canterbury.

[9] On 23 July 2020, IAG announced that AMI would be closing all of its 53 branches and its remaining State office in New Zealand in phases.