To get ready for the shift Nib has begun selling international medical cover in New Zealand, which it hopes to launch in Australia within 18 months.

The $1.2 billion insurer already insures 20,000 workers and 35,000 students who travel to Australia. But insuring locals who travel overseas is an "underdeveloped market", Mr Fitzgibbon told The Australian Financial Review.

"The opportunity we see is to provide cover for Australians and New Zealanders going and living overseas," he said. "I'll say in 50 years to be safe, but it may be 10, people will demand health insurance that covers them no matter where they are."

Mr Fitzgibbon outlined the plans to investors at the company's annual general meeting in Sydney on Wednesday.

He also told shareholders that Nib would beat the 2 to 3 per cent growth in policyholders expected for the $19 billion sector.

One tactic to ensure Nib's outperformance would be to drive membership among older people through a deal with Suncorp-owned APIA, which was announced in May and recently began. The tie-up sees Nib cover sold under the APIA brand, to ensure Nib does not "compromise" its traditional market position as an insurer targeting the under 40s market.

Mr Fitzgibbon said he did not expect the $4 billion float of Medibank Private would lead his competitor to ramp up its attempts to lure members from Nib's core audience. "The under 40s market is already a very competitive market," he said. "Medibank Private go after that market through their ahm brand, for example."

One thing that will change when Medibank lists next month is Nib will lose its status as the market's only listed health insurer. The stock has gained about 30 per cent in the past year. It fell 1.6 per cent to $3.12 on Wednesday, down from a 12-month high of $3.50 hit in September.

The company's new medical tourism business, Nib Options, would not be profitable until the 2016 financial year, Mr Fitzgibbon said. The business, launched in March this year, links Australians with dentists and cosmetic surgeons in countries such as Thailand. The company recently beefed up its marketing efforts, but Nib Options was still in a testing phase, he said. "Everyday we're learning something new about the business of medical travel."

Mr Fitzgibbon reaffirmed guidance provided at the full-year results, that Nib will deliver consolidated operating profit for the 2015 financial year in the range of $75 million to $82 million.