The head of ACC says they're working hard on improving rehabilitation performance.  

The government agency has reported a $7.2 billion deficit a year after posting an almost $1 billion surplus.  

It says the cost of services and compensation rose 16% over the year.  

It's proposing to hike levies for vehicle owners, workers, and business owners.  

ACC Chief Executive Megan Main told Mike Hosking levies have been held flat or reduced in the last decade, while costs have been increasing. 

She says they need to make sure over the long-term the settings are right, to balance costs with how much money is coming in. 

Main says the big driver of the deficit is the re-calculation of the lifetime costs of injuries that have already occurred. 

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• ACC needs to "lift its game" after reporting $7.2b deficit, Minister says